Evidence Level
Limited
5 Clinical Trials
6 Documented Benefits
2/5 Evidence Score

Royal jelly is the nutrient-rich secretion that nurse bees produce to feed queen bees, used as a supplement for energy, immune support, skin health, and women's hormonal and menopausal support. It contains unique fatty acids and proteins, including a distinctive compound called 10-HDA that is of particular research interest. The doses tested in placebo-controlled trials run from 800 mg/day of enzyme-treated royal jelly powder up to about 3 g/day, with 1,000 mg/day of capsules the dose used in the menopausal and premenstrual trials. Amounts around 300 mg/day are widely sold but appear in none of the trials cited here. It is sold fresh, freeze-dried, or in capsules. Most people tolerate royal jelly, but it is a documented cause of IgE-mediated allergy: reported reactions include hives, facial swelling, bronchospasm, acute asthma and anaphylaxis, and a death from royal jelly induced asthma was reported in the Medical Journal of Australia in 1994. Anyone with asthma, atopy (hay fever, eczema, food allergy) or an allergy to bees or bee products should not take it. Reactions have occurred on a first dose through cross-reactivity with common inhalant allergens, so starting small is not a safeguard.

Studied Dose 1,000 mg/day of royal jelly capsules for 8 weeks in menopausal and PMS trials; other trials used 800 to about 3,150 mg/day; no trial on this page used 500 mg/day.
Active Compound Major Royal Jelly Proteins (MRJPs), 10-hydroxy-2-decenoic acid (10-HDA), B-vitamins, sterols.

Benefits

Menopausal symptom relief — modest

Royal jelly at 800 to 1,000 mg/day for 8 to 12 weeks lowers menopausal symptom scores in postmenopausal women, most clearly for anxiety and low back pain. Read the two trials carefully. The larger one (200 Iranian women, 1,000 mg/day, 8 weeks) reports that scores fell significantly within the royal jelly group and not within the placebo group, which is not the same thing as a significant difference between the groups. The smaller one (42 Japanese women, 800 mg/day of enzyme-treated royal jelly, 12 weeks) did compare the groups directly and found significance on two scores, anxiety (p=0.046) and backache and low back pain (p=0.040), but five of its six authors are employees of the royal jelly company that supplied the product and the sixth was paid an advisory fee by it. A 2026 meta-analysis in Menopause pooled only 2 of its 6 included trials (312 of 471 women) for a standardised mean difference of 0.73 (95% CI 0.50 to 0.96), graded moderate quality. Reasonable consideration for women looking for botanical menopause support, particularly for the mood and physical-symptom aspects. Not a substitute for HRT in severe vasomotor disease.

Mood support during menopause

Some trials report improvements in anxiety, mood, and quality of life with royal jelly supplementation — most relevant for menopausal women experiencing perimenopausal mood changes. Effect sizes are small to moderate, and trial quality varies. Reasonable adjunct for mild mood symptoms in the menopausal transition. Don't choose royal jelly specifically for clinical depression — saffron, EPA-rich omega-3, and SSRIs all have stronger evidence for mood disorders.

Possible modest lipid effects

Two small controlled trials report reductions in total cholesterol and LDL. In 40 adults with mild hypercholesterolaemia taking about 3.15 g/day for 3 months, total cholesterol fell from 207 to 183 mg/dL and LDL from 126 to 120 mg/dL, reported as change from baseline within the royal jelly arm rather than as a comparison against placebo. In a second study, 7 of 15 volunteers took 6 g/day for 4 weeks and their total cholesterol and LDL fell significantly against the control group. HDL did not change in either study, and both used doses several times larger than a typical royal jelly capsule. Not validated as a lipid-lowering intervention. If lipid management is the priority, oat beta-glucan, plant sterols, or red yeast rice all have substantially stronger evidence than royal jelly.

Fertility: no human trial evidence for oral royal jelly

Royal jelly has a long history as a folk tonic and fertility aid, and it changes reproductive measures in rodents and livestock. That is where the evidence stops. A PubMed search for royal jelly restricted to randomized controlled trials returns 29 records, and the reproduction studies among them are in ewes, laying hens and broiler chicks; no human trial in that set measured a fertility outcome from a royal jelly product you swallow. The one human fertility study is a crossover study in 99 Egyptian couples with asthenozoospermia (2008) that applied a honey and royal jelly mixture intravaginally around ovulation, which is neither an oral supplement nor royal jelly on its own. Beyond that there is a single 2026 case report of one woman with diminished ovarian reserve who conceived after taking royal jelly proteins, and its authors call it non-generalisable. Do not buy royal jelly for fertility.

Skin health — limited evidence

Royal jelly is included in many topical and oral skincare products, with marketing claims around anti-aging and skin appearance. 10-HDA shows effects on skin cells in the laboratory. The human trials that exist are mostly of royal jelly applied to the face, not swallowed, and topical results do not tell you what a capsule does. Restricting a PubMed search of royal jelly to randomized controlled trials returns 29 records, and the only oral skin study among them is a two-page double-blind placebo-controlled report on skin barrier function in the European Journal of Dermatology (2018), for which no results abstract is indexed. That is the whole oral evidence base for skin. Most skin claims for royal jelly outpace the actual evidence base substantially.

Allergy risk — important safety note

Royal jelly can trigger severe allergic reactions, including anaphylaxis, in people with bee or pollen allergies. Asthma exacerbation has also been reported. Test cautiously and avoid entirely if you have known bee product or pollen allergies. This is an important practical limitation that often gets underplayed in royal jelly marketing — the safety profile isn't as benign as the 'natural superfood' framing implies.

Mechanism of action

1

Mild Estrogenic Activity

Some royal jelly components show weak estrogenic activity in vitro, potentially binding estrogen receptors at low affinity. This may underlie the menopausal symptom benefits — though effects are far weaker than estrogens or even traditional phytoestrogens (genistein, daidzein).

2

10-Hydroxy-2-Decenoic Acid (10-HDA) Bioactivity

10-HDA is a unique fatty acid found only in royal jelly. It shows multiple biological activities in vitro: antibacterial, anti-inflammatory, immunomodulatory, and weak estrogen receptor binding. It is the standard quality marker for royal jelly, and ISO 12824:2016 sets a minimum of 1.4 g of 10-HDA per 100 g of fresh royal jelly and 3.5 g per 100 g of freeze-dried royal jelly. Whether the jar in front of you meets that is a separate question: most royal jelly capsules carry no 10-HDA figure on the label, and of the trials cited here only the 800 mg/day Japanese trial reported the 10-HDA content of its product (at least 3.5% 10-HDA and 0.6% 10-HDAA). A product with no stated 10-HDA cannot promise it matches what was tested.

3

Major Royal Jelly Proteins (MRJPs)

MRJPs (especially MRJP1, also called royalactin) constitute ~80% of royal jelly proteins. They have antimicrobial, antioxidant, and immune-modulating activities in vitro. MRJP3 is also a major allergen — implicated in cross-reactivity with honeycomb in anaphylaxis cases.

4

Antioxidant Activity

Royal jelly contains phenolic compounds, flavonoids, and unique fatty acids with antioxidant activity. Some clinical trials show modest reductions in oxidative stress markers.

5

Immunomodulatory Effects

Royal jelly modulates cytokine profiles in vitro — generally toward an anti-inflammatory pattern. The clinical relevance for autoimmune conditions or general immune health is not well-established.

Clinical trials

1
Royal Jelly for Menopausal Symptoms (Randomized, Placebo-Controlled)
PubMed

Double-blind, randomized, placebo-controlled trial. 1,000 mg royal jelly capsules daily or placebo for 8 weeks in postmenopausal women aged 45-60 in Bandar Abbas, Iran. Conducted June to November 2018. (Sharif SN, Darsareh F. Complement Ther Clin Pract 2019;37:47-50. PMID 31470366)

200 postmenopausal women aged 45-60.

Mean baseline menopausal score did not differ between groups. After 8 weeks, the menopausal symptom score reduced significantly in the royal jelly group whereas reduction was not significant in the placebo group. Authors concluded daily 1,000 mg royal jelly was effective for alleviating menopausal symptoms and that further research is necessary to confirm the effect. Note what is reported and what is not: the result is given as a significant fall within the royal jelly group and a non-significant fall within the placebo group, which is not the same as a significant royal jelly versus placebo difference, and no such between-group figure is given.

2
Enzyme-Treated Royal Jelly for Japanese Postmenopausal Women
PubMed

Double-blind, randomized, placebo-controlled trial. 800 mg/day enzyme-treated royal jelly powder vs. placebo (800 mg dextrin) for 12 weeks. Menopausal symptoms assessed every 4 weeks via Japanese-women-specific questionnaire. The test product was protease-digested lyophilised royal jelly standardised to at least 3.5% 10-HDA and 0.6% 10-HDAA. (Asama T, Matsuzaki H, Fukushima S, Tatefuji T, Hashimoto K, Takeda T. Evid Based Complement Alternat Med 2018;2018:4868412. PMID 29853955)

42 healthy Japanese postmenopausal women (21 per arm). 12-week intervention.

Significant differences in anxiety score (p=0.046) and backache/low back pain score (p=0.040) between RJ and placebo at 12 weeks. No significant differences at 4 weeks. No side effects were observed. Who ran it matters here: five of the six authors are employees of Yamada Bee Company, a royal jelly producer that supplied the test product, and the sixth received a medical advisory fee from the same company. No independent group has replicated this product. Important: Japanese menopausal symptoms differ from Western patterns (more neck stiffness/back pain, fewer hot flashes) — may explain the specific symptom domain effects.

3
SYSTEMATIC REVIEW AND META-ANALYSIS (not a trial): Royal Jelly for Postmenopausal Symptoms
PubMed

Evidence review and pooled analysis of randomized controlled trials evaluating royal jelly for management of postmenopausal symptoms. This is a pooled analysis of other researchers' trials, not a new trial in people. (Ferraz SD, Stangherlin L, Colonetti T, Rodrigues Uggioni ML, Specht Taschetto I, Ceretta L, Grande AJ, Rosa MID. Menopause 2026;33(4):501-509. PMID 41401249)

6 clinical trials, 471 postmenopausal women (from 281 studies identified).

Royal jelly supplementation significantly improved postmenopausal symptoms vs. placebo. The pooled standardised mean difference of 0.73 (95% CI 0.50 to 0.96, p<0.00001, I-squared 0%, moderate-quality evidence by GRADE) comes from only 2 of the 6 included studies, covering 312 of the 471 women. The other 4 studies were included in the review but were not pooled into that estimate. Authors concluded RJ may offer a promising nonhormone option for managing menopausal symptoms, particularly for women who cannot use hormone therapy. Databases searched through May 2025 (MEDLINE, LILACS, Embase, Cochrane Library); the included studies were published between 2011 and 2021. The authors reported no conflicts of interest.

4
CASE SERIES, NOT A TRIAL: 7 People Harmed by Royal Jelly (Asthma and Anaphylaxis)
PubMed

Case series and immunologic investigation of seven subjects with asthma and/or anaphylaxis following royal jelly ingestion. Skin-prick tests, IgE immunoassays, and protein blotting performed. This is a harms report, not efficacy evidence. It comes from the same Alfred Hospital group in Melbourne as the 1995 report below and continues the same line of work, so the two should be read as one series rather than as two independent confirmations. (Thien FC, Leung R, Baldo BA, Weiner JA, Plomley R, Czarny D. Clin Exp Allergy 1996;26(2):216-222. PMID 8835130)

7 subjects who developed asthma and (in some cases) anaphylaxis after royal jelly ingestion. 6 of 7 female; all atopic with positive grass pollen reactions. Three of seven also tested with bee venom — negative reactions.

Skin-prick tests, immunoassays, and protein blotting confirmed IgE-mediated true hypersensitivity reactions. 18 different IgE-binding components detected on royal jelly protein blots; one ~55 kDa component bound by all reactive sera. Notably, 38% of bee-venom-allergic subjects (out of 63 sera tested) and 52% of subjects with inhalant/food allergies (out of 75 sera) showed IgE reactivity to royal jelly proteins — suggesting cross-reactivity with common environmental allergens. The authors add two caveats: there was no direct relationship between IgE reactivity to bee venom allergens and to royal jelly proteins, and the clinical meaning of the antibodies found in the control sera is unknown. Separately, a fatal case of royal jelly induced asthma was reported in the Medical Journal of Australia in 1994 (Bullock RJ, Rohan A, Straatmans JA, 160(1):44, PMID 8271989), which is why this is not a minor tolerability footnote.

5
CASE SERIES, NOT A TRIAL: Royal Jelly-Induced Asthma and Anaphylaxis
PubMed

Original report of royal jelly induced asthma and anaphylaxis, with clinical characteristics and immunologic correlations. This is a harms report, not efficacy evidence, and it comes from the same Alfred Hospital group in Melbourne as the 1996 report above rather than being an independent confirmation of it. (Leung R, Thien FC, Baldo B, Czarny D. J Allergy Clin Immunol 1995;96(6 Pt 1):1004-1007. PMID 8543734)

5 atopic patients with reactions to royal jelly.

Documents IgE-mediated hypersensitivity reactions to royal jelly in atopic individuals. Together with the 1996 immunologic follow-up from the same group, this is the report that established royal jelly as a recognised cause of anaphylaxis. Cross-reactivity with other inhalant allergens may explain why a reaction can happen on a first ingestion.

Side effects and drug interactions

Common Potential side effects

Severe allergic reactions, and this is the main reason to be careful with royal jelly. Reported reactions include urticaria, facial and eyelid swelling, bronchospasm, acute asthma and anaphylaxis, and they are IgE-mediated: skin-prick testing, specific IgE immunoassay and protein blotting in an Australian series of 7 people confirmed true IgE-mediated hypersensitivity, with 18 IgE-binding royal jelly components detected and one of about 55 kDa bound by every reactive serum. A death from royal jelly induced asthma was reported in the Medical Journal of Australia in 1994. Risk is concentrated in atopic people: in a Hong Kong survey, all but one of the 36 people with a positive royal jelly skin test were also allergic to other common allergens, and a positive royal jelly skin test carried an odds ratio of 33.73 (95% CI 4.51 to 252.11) for atopy. Reactions can occur on the very first ingestion because royal jelly proteins cross-react with common inhalant allergens, so there is no safe test dose.
Itching, hives, contact dermatitis (topical use).
Possible GI upset (nausea, abdominal pain) at higher doses.
Acute asthma has been triggered by royal jelly, including a reported fatal attack (Med J Aust 1994). Do not use royal jelly if you have asthma.
Possible hormonal effects — relevant for hormone-sensitive conditions (e.g., estrogen receptor-positive breast cancer history).
Haemorrhagic colitis: one published case, a 53-year-old woman with abdominal pain and bloody diarrhoea after 25 days of royal jelly, with haemorrhagic oedematous mucosa over 20 cm of sigmoid colon on colonoscopy. Symptoms cleared within days and the lesions within two weeks of stopping. The case report does not describe a very high dose.
Pregnancy and lactation: insufficient safety data — avoid.

Important Drug interactions

Warfarin: one published case, an 87-year-old man on stable warfarin (INR 1.9 to 2.4) who presented with haematuria and an INR of 6.88, rising to 7.29 in hospital, one week after starting royal jelly. That is a single case report, not a study, but it is reason enough to avoid royal jelly on warfarin or to monitor INR closely if you take both.
Antihypertensive medications: theoretical additive blood pressure effects.
Hormone-related medications (HRT, tamoxifen, aromatase inhibitors): theoretical interaction via weak estrogenic activity.
Asthma medications: avoid royal jelly entirely if asthmatic — risk of severe bronchospasm.
Bee product allergies (honey, propolis, bee venom): cross-reactivity risk; avoid royal jelly.

Frequently asked questions about Royal Jelly

What is royal jelly used for?

Royal jelly is the nutrient-rich secretion that nurse bees feed to queen bees. As a supplement it is used for energy, immune support, skin health, and women's hormonal and menopausal support, and it contains unique fatty acids and proteins.

What is royal jelly good for?

It is studied for antioxidant and immune support, menopausal symptom relief, skin health, and general vitality, though human evidence is mixed. Its distinctive compound 10-HDA is of particular research interest.

How much royal jelly should I take?

The doses tested in placebo-controlled trials are 800 mg/day of enzyme-treated (protease-digested) royal jelly powder for 12 weeks, 1,000 mg/day of royal jelly capsules for 8 weeks and for 2 menstrual cycles, and roughly 3 g/day of fresh-equivalent royal jelly for 3 to 6 months. Smaller amounts such as 300 mg/day are widely sold but appear in none of the trials cited here. Royal jelly is available fresh, freeze-dried, or in capsules.

Is royal jelly safe?

Most people tolerate it, but royal jelly causes true IgE-mediated allergic reactions in a minority. Reported reactions include hives, facial and eyelid swelling, bronchospasm, acute asthma and anaphylaxis, and one fatal asthma attack after royal jelly ingestion was reported in the Medical Journal of Australia in 1994. The risk is concentrated in atopic people: in a Hong Kong survey of 1,472 hospital employees, 31% had taken royal jelly and 9 reported adverse reactions, while skin testing to pure royal jelly was positive in 7.4% of 176 survey respondents and 7.3% of 300 asthma clinic patients. A positive royal jelly skin test was strongly linked to being allergic to other common allergens (odds ratio 33.7), though the authors note the link between a positive test and an actual clinical reaction remains to be defined. If you have asthma, hay fever, eczema, food allergy, or any allergy to bees or bee products, do not take royal jelly. Some people react on their very first dose because royal jelly proteins cross-react with common inhalant allergens, so a small trial dose does not make it safe.

What is Royal Jelly?

Royal jelly is the nutrient-rich secretion that nurse bees produce to feed queen bees, used as a supplement for energy, immune support, skin health, and women's hormonal and menopausal support.

What is the recommended dosage of Royal Jelly?

The clinically studied dose is 1,000 mg/day of royal jelly capsules for 8 weeks in menopausal and PMS trials; other trials used 800 to about 3,150 mg/day; no trial on this page used 500 mg/day. Always follow the product label and check with a healthcare provider for personal advice.

Is Royal Jelly safe, and does it have side effects?

For most healthy adults, Royal Jelly is well tolerated at studied doses. Reported effects can include: Severe allergic reactions, and this is the main reason to be careful with royal jelly. Reported reactions include urticaria, facial and eyelid swelling, bronchospasm, acute asthma and anaphylaxis, and they are IgE-mediated: skin-prick testing, specific IgE immunoassay and protein… It may also interact with some medications. Royal Jelly is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Royal Jelly interact with any medications?

Possible interactions include: Warfarin: one published case, an 87-year-old man on stable warfarin (INR 1.9 to 2.4) who presented with haematuria and an INR of 6.88, rising to 7.29 in hospital, one week after starting royal jelly. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Royal Jelly?

NutraSmarts rates the evidence for Royal Jelly as Limited (2 out of 5). It is backed by 5 clinical trials and 15 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(15 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Sharif SN, Darsareh F Effect of royal jelly on menopausal symptoms: A randomized placebo-controlled clinical trial Complement Ther Clin Pract. 2019;37:47-50. doi:10.1016/j.ctcp.2019.08.006.PubMedUsed to support: Randomized, double-blind, placebo-controlled trial in 200 Iranian postmenopausal women aged 45 to 60 taking 1,000 mg/day of royal jelly or placebo for 8 weeks in Bandar Abbas, June to November 2018. Baseline menopausal scores were similar between groups; after 8 weeks the score fell significantly within the royal jelly group and did not fall significantly within the placebo group. The reported result is a within-arm change rather than a statistical comparison of royal jelly against placebo, and the authors state further research is necessary to confirm the effect.
  2. Chiu HF, Chen BK, Lu YY, Han YC, Shen YC, Venkatakrishnan K, Golovinskaia O, Wang CK Hypocholesterolemic efficacy of royal jelly in healthy mild hypercholesterolemic adults Pharm Biol. 2017;55(1):497-502. doi:10.1080/13880209.2016.1253110.PubMedUsed to support: Randomized, placebo-controlled trial in 40 adults with mild hypercholesterolaemia (180 to 200 mg/dL) taking nine 350 mg royal jelly capsules daily, about 3.15 g/day, or placebo for 3 months. Total cholesterol fell from 207 to 183 mg/dL and LDL cholesterol from 126 to 120 mg/dL after royal jelly (p<0.05), while triglycerides and HDL were not considerably altered, DHEA-S rose, and liver and kidney tests were unaffected. The reported result is a change after supplementation rather than a head-to-head comparison against placebo, and 40 people is a small sample.
  3. Matsushita H, Shimizu S, Morita N, Watanabe K, Wakatsuki A Effects of royal jelly on bone metabolism in postmenopausal women: a randomized, controlled study Climacteric. 2021;24(2):164-170. doi:10.1080/13697137.2020.1806815.PubMedUsed to support: Randomized, double-blind, placebo-controlled trial in 72 healthy postmenopausal women aged 45 to 60 and within 5 years of menopause, taking dried royal jelly equivalent to 3,000 mg of fresh royal jelly or placebo daily for 6 months. Over 6 months the placebo group lost femoral bone mineral density significantly and deteriorated on hip structural analysis, while no significant change was found in those measures in the royal jelly group. The bone turnover markers P1NP and tartrate-resistant acid phosphatase fell significantly in the placebo group, and P1NP did not change significantly in the royal jelly group. The authors conclude royal jelly may ameliorate decreases in femoral bone density and strength. The finding rests on a difference in within-group significance rather than a reported royal jelly versus placebo comparison. This trial measured bone density and bone turnover, not fertility.
  4. Bullock RJ, Rohan A, Straatmans JA Fatal royal jelly-induced asthma Med J Aust. 1994;160(1):44..PubMedUsed to support: Reports a death from asthma following royal jelly ingestion, published as a letter responding to an earlier Medical Journal of Australia report of royal jelly induced asthma. The letter carries no abstract, so the published record establishes that a fatality occurred rather than the clinical detail of the case.
  5. Leung R, Thien FC, Baldo B, Czarny D Royal jelly-induced asthma and anaphylaxis: clinical characteristics and immunologic correlations J Allergy Clin Immunol. 1995;96(6 Pt 1):1004-1007. doi:10.1016/s0091-6749(95)70242-3.PubMedUsed to support: Original report of royal jelly induced asthma and anaphylaxis with clinical characteristics and immunologic correlations, from the same Alfred Hospital group in Melbourne that published the 1996 immunologic study. No abstract is indexed for this article, so its numbers and patient details are not in the public record. It is a harms report rather than efficacy evidence, and the same line of work as the 1996 paper rather than an independent confirmation.
  6. Thien FC, Leung R, Baldo BA, Weiner JA, Plomley R, Czarny D Asthma and anaphylaxis induced by royal jelly Clin Exp Allergy. 1996;26(2):216-222. doi:10.1111/j.1365-2222.1996.tb00082.x.PubMedUsed to support: Case series of 7 people who developed asthma, in some cases with anaphylaxis, after eating royal jelly. Skin-prick tests, IgE immunoassays and protein blotting confirmed true IgE-mediated hypersensitivity, with 18 IgE-binding royal jelly components detected and one of about 55 kDa bound by every reactive serum. IgE reactivity to royal jelly was also found in 38% of 63 bee-venom-allergic sera and 52% of 75 sera from people with inhalant or food allergy, though the authors state there is no direct relationship between bee venom and royal jelly IgE reactivity and that the clinical meaning of the control-serum antibodies is unknown. Seven patients, a harms report rather than a trial, and the same line of work as the 1995 report by this group.
  7. Leung R, Ho A, Chan J, Choy D, Lai CK Royal jelly consumption and hypersensitivity in the community Clin Exp Allergy. 1997;27(3):333-336..PubMedUsed to support: Cross-sectional survey of 1,472 hospital employees in Hong Kong. 461 (31.3%) had taken royal jelly, and 9 subjects reported 14 adverse reactions including urticaria, eczema, rhinitis and acute asthma. Skin testing to pure royal jelly was positive in 13 of 176 survey respondents (7.4%) and 23 of 300 consecutive asthma clinic attendees (7.3%); all but one of the 36 skin-test-positive subjects were atopic to other common allergens, and a positive royal jelly skin test was strongly associated with atopy (odds ratio 33.73, 95% CI 4.51 to 252.11). A survey, not a trial, and the authors note the relationship between skin test positivity and actual clinical reactions remains to be defined.
  8. Yonei Y, Shibagaki K, Tsukada N, Nagasu N, Inagaki Y, Miyamoto K, Suzuki O, Kiryu Y Case report: haemorrhagic colitis associated with royal jelly intake J Gastroenterol Hepatol. 1997;12(7):495-499. doi:10.1111/j.1440-1746.1997.tb00472.x.PubMedUsed to support: Single case of a 53-year-old woman with abdominal pain and bloody diarrhoea after taking royal jelly for 25 days. Colonoscopy showed haemorrhagic, oedematous mucosa throughout 20 cm of sigmoid colon, and a drug-induced lymphocyte stimulation test was slightly positive for royal jelly. Symptoms resolved within a few days and the colonic lesions within two weeks on conservative therapy. One case report, so it shows this can happen, not how often.
  9. Lee NJ, Fermo JD Warfarin and royal jelly interaction Pharmacotherapy. 2006;26(4):583-586. doi:10.1592/phco.26.4.583.PubMedUsed to support: Single case of an 87-year-old man whose INR had been stable at 1.9 to 2.4 on long-term warfarin and who presented with haematuria and an INR of 6.88, rising to 7.29 in hospital, one week after starting royal jelly. The authors note no other change in his drugs, diet or condition. A case report rather than a pharmacokinetic study, and the only published human signal for this interaction.
  10. Guo H, Saiga A, Sato M, Miyazawa I, Shibata M, Takahata Y, Morimatsu F Royal jelly supplementation improves lipoprotein metabolism in humans J Nutr Sci Vitaminol (Tokyo). 2007;53(4):345-348. doi:10.3177/jnsv.53.345.PubMedUsed to support: Controlled study in 15 volunteers, 7 of whom took 6 g/day of royal jelly for 4 weeks. Serum total cholesterol and LDL fell significantly compared with the control group (p<0.05), while HDL and triglycerides did not differ, and small very-low-density lipoprotein decreased. Fifteen people is a very small sample, the dose is far above what royal jelly capsules typically provide, and the work was carried out at a food company research centre.
  11. Abdelhafiz AT, Muhamad JA Midcycle pericoital intravaginal bee honey and royal jelly for male factor infertility Int J Gynaecol Obstet. 2008;101(2):146-149. doi:10.1016/j.ijgo.2007.11.012.PubMedUsed to support: Crossover study in 99 Egyptian couples with asthenozoospermia comparing midcycle pericoital intravaginal application of a bee honey and royal jelly mixture against intrauterine insemination. Across 553 cycles analysed there were 23 pregnancies (8.1% per cycle) with the honey and royal jelly mixture versus 7 (2.6%) with insemination (p<0.001). The preparation was placed in the vagina rather than swallowed, and it was a honey and royal jelly mixture rather than royal jelly alone, so it does not show what an oral royal jelly supplement does.
  12. Morita H, Ikeda T, Kajita K, Fujioka K, Mori I, Okada H, Uno Y, Ishizuka T Effect of royal jelly ingestion for six months on healthy volunteers Nutr J. 2012;11:77. doi:10.1186/1475-2891-11-77.PubMedUsed to support: Randomized, double-blind, placebo-controlled trial in 61 healthy volunteers aged 42 to 83 taking 3,000 mg/day of royal jelly in 100 mL of liquid or placebo for 6 months; 30 royal jelly and 26 placebo participants were analysed. Adjusted mean changes differed between groups for red blood cell count, haematocrit, fasting plasma glucose, insulinogenic index, DHEA-S, testosterone, the testosterone to DHEA-S ratio, and the mental health subscale of the SF-36. Many outcomes were tested at once without a single prespecified primary endpoint, so the individual findings need replication, but the trial does show 3 g/day was tolerated for 6 months.
  13. Asama T, Matsuzaki H, Fukushima S, Tatefuji T, Hashimoto K, Takeda T Royal Jelly Supplementation Improves Menopausal Symptoms Such as Backache, Low Back Pain, and Anxiety in Postmenopausal Japanese Women Evid Based Complement Alternat Med. 2018;2018:4868412. doi:10.1155/2018/4868412.PubMedUsed to support: Randomized, placebo-controlled trial in 42 healthy Japanese postmenopausal women taking 800 mg/day of protease-digested lyophilised royal jelly, standardised to at least 3.5% 10-HDA and 0.6% 10-HDAA, or 800 mg dextrin placebo for 12 weeks. All 42 completed. Between-group differences reached significance at 12 weeks for anxiety (p=0.046) and for backache and low back pain (p=0.040), with no significant differences at 4 weeks, and no side effects were observed in either group. Five of the six authors are employees of Yamada Bee Company, a royal jelly producer that supplied the test product, and the sixth received a medical advisory fee from the same company.
  14. Ferraz SD, Stangherlin L, Colonetti T, Rodrigues Uggioni ML, Specht Taschetto I, Ceretta L, Grande AJ, Rosa MID Royal jelly for management of postmenopausal symptoms: a systematic review and meta-analysis Menopause. 2026;33(4):501-509. doi:10.1097/GME.0000000000002688 (published online 2025).PubMedUsed to support: Systematic review searching MEDLINE, LILACS, Embase and the Cochrane Library through May 2025. Of 281 records identified, 6 studies in 471 postmenopausal women, published between 2011 and 2021, were included. The pooled standardised mean difference favouring royal jelly was 0.73 (95% CI 0.50 to 0.96, p<0.00001, I-squared 0%, moderate quality by GRADE), and that estimate is drawn from only 2 of the 6 studies, covering 312 women. A review of existing trials, not a new trial. The authors report no conflicts of interest.
  15. Pi X, Yang Y, Guo Q, Shen L Spontaneous pregnancy in a woman with diminished ovarian reserve following dietary supplementation with major royal jelly proteins: A case report Medicine (Baltimore). 2026;105(25):e49345. doi:10.1097/MD.0000000000049345.PubMedUsed to support: A single 35-year-old woman with hormonally diagnosed diminished ovarian reserve conceived naturally after 4 weeks of taking 1 g of lyophilised major royal jelly protein powder twice daily, with no gastrointestinal or allergic reactions reported. The authors describe the observation as non-generalisable, note that lifestyle confounders were not objectively monitored, and state that a randomized double-blind trial has been arranged. One person, no control group.