Home Ingredients Chrysin (5,7-Dihydroxyflavone)

Chrysin (5,7-Dihydroxyflavone)

Passiflora caerulea (passionflower); also concentrated in honey, propolis and Oroxylum indicum
Evidence Level
Preliminary
3 Clinical Trials
5 Documented Benefits
1/5 Evidence Score

Chrysin is a flavone found in honey, propolis and some plants, including passionflower and Oroxylum indicum. It is sold mainly as a testosterone booster, on the idea that it blocks aromatase, the enzyme that turns testosterone into estrogen. That effect shows up in cell studies but has not held up in people. Swallowed chrysin is poorly absorbed: a 400 mg dose gave peak blood levels of only 3 to 16 ng/mL, and most of the dose passed out unchanged in the stool. In young men, daily propolis and honey supplying chrysin did not change urinary testosterone, and in two randomized trials of stacks that included 625 mg a day of chrysin, estradiol rose rather than fell. A micellar form combined with quercetin and rutin roughly doubles blood levels, but no form of chrysin has yet shown a health benefit in people.

Studied Dose 400 mg as a single oral dose in the absorption study; 625 mg a day for 4 to 8 weeks as one ingredient of androstenedione stacks in two trials. Labels commonly suggest 500 to 3,000 mg a day, and no trial has shown a benefit at those doses.
Active Compound Chrysin (5,7-dihydroxyflavone), a natural flavone. Found in honey and propolis, and in Passiflora caerulea (passionflower); also found in Oroxylum indicum, which has its own ingredient page.

Benefits

Testosterone levels in men

In a 21-day controlled study of 20 healthy young men, the 10 who took propolis tablets (1,280 mg) plus honey each day, both natural chrysin sources, showed no change in urinary testosterone compared with baseline or with the 10 controls. In two randomized trials, stacks providing 625 mg a day of chrysin alongside androstenedione also left total testosterone unchanged.

Supported by Trial 1

Estrogen conversion (aromatase) in people

Chrysin blocks aromatase in cell studies, but in two randomized trials (20 young men for 8 weeks and 55 men aged 30 to 59 for 28 days), stacks with 625 mg a day of chrysin did not stop estradiol from rising; it rose 103 percent in the older men. Chrysin was one of several ingredients, so its own effect cannot be separated.

Supported by Trial 3, Trial 1

Antioxidant activity in laboratory studies

Chrysin shows antioxidant and anti-inflammatory activity in laboratory studies, but no human trial has measured either after oral chrysin. Blood levels after a 400 mg dose, roughly 0.01 to 0.06 micromolar, sit far below the micromolar concentrations that are active in cell experiments.

Supported by Trial 2, Trial 3

Use alongside irinotecan in a clinical safety study

Twenty people with advanced colorectal cancer took chrysin for a week before and after each irinotecan infusion in an uncontrolled safety study. No side effects were blamed on chrysin and severe (grade 3) delayed diarrhea occurred in 10 percent, but with no control group, prevention was not tested. Do not add any supplement during chemotherapy without your oncologist.

Supported by Trial 2, Trial 3

Calming effects: tested for passionflower, not for chrysin

Chrysin is one of many compounds in passionflower, and whole passionflower extracts have been tested in people for anxiety. Isolated chrysin has not been tested for calm or mood in any human trial, so effects seen with the whole plant cannot be credited to chrysin.

Supported by Trial 3, Trial 1

Mechanism of action

1

Aromatase (CYP19A1) inhibition in lab studies

A systematic review found 20 studies of chrysin and aromatase. All but one showed inhibition, but 17 were cell studies and 2 were in rats. The only human study, in which propolis and honey supplied the chrysin, found no change in testosterone.

2

Poor oral absorption

After a 400 mg oral dose in seven volunteers, peak blood chrysin was 3 to 16 ng/mL, chrysin sulfate ran about 30 times higher, and most of the dose was recovered unchanged in stool. The researchers put this down to extensive metabolism and pumping of metabolites back into the gut.

3

Gut enzyme (UGT1A1) induction

Chrysin increases the enzyme UGT1A1 in intestinal cell studies, which was the reason it was given with irinotecan. In patients, the blood ratio of inactive to active irinotecan metabolite was about the same as in earlier patients who did not take chrysin, so this effect was not confirmed in people.

4

Methylated relatives absorb better (rats)

5,7-dimethoxyflavone, a methylated relative of chrysin, was well absorbed and built up in tissue in rats where chrysin was not, and was about 10 times more potent against cancer cell growth in lab tests. This is cell and rat work and says nothing about chrysin itself in people.

Clinical trials

1
Chrysin-rich propolis and honey on testosterone in men
PubMed

Controlled study of daily propolis tablets and honey, both natural chrysin sources, for 21 days, with urinary testosterone measured by GC/MS at baseline and on days 7, 14 and 21 (Gambelunghe et al. 2003, J Med Food)

20 healthy men aged 25 to 30, 10 taking 1,280 mg of propolis tablets plus honey each morning and 10 controls, as described in a 2020 systematic review. The chrysin dose delivered is not stated.

Urinary testosterone did not change at any time point compared with baseline or with controls. The authors concluded that these foods, at doses usually taken as supplements, do not affect testosterone balance in men.

2
Oral chrysin absorption in healthy volunteers (single 400 mg dose)
PubMed

Human pharmacokinetic study measuring chrysin and its metabolites in plasma, urine and feces after one oral dose (Walle et al. 2001, Br J Clin Pharmacol)

Seven healthy adult volunteers given a single 400 mg oral dose of chrysin.

Peak plasma chrysin was only 3 to 16 ng/mL, with an AUC of 5 to 193 ng/mL/h, and plasma chrysin sulfate was about 30 times higher. Urine held 0.2 to 3.1 mg of chrysin and 2 to 26 mg of chrysin glucuronide, and most of the dose came out in the feces as unchanged chrysin. The authors concluded that oral chrysin has low bioavailability. No health outcome was measured.

3
Systematic review of chrysin and aromatase
PubMed

Systematic review of studies on chrysin and aromatase inhibition, screening 1,721 records (Balam et al. 2020, Heliyon)

No participants of its own. Of 20 included studies, 17 were in vitro, 2 in rats and 1 in humans.

All but one included study found that chrysin inhibited aromatase, and the authors concluded it has aromatase-inhibiting potency. That conclusion rests on cell and rat studies. The single human study found no change in urinary testosterone, and the review did not show that oral chrysin lowers estrogen or raises testosterone in people.

Side effects and drug interactions

Common Potential side effects

In a 30-day study of 15 adults taking a micellar chrysin, quercetin and rutin product daily, side effects were mild and reversible.
Mutagenicity in lab tests: chrysin was mutagenic in human HepG2 liver cells at 1 to 15 micromolar and in a Salmonella bacterial test, and it inhibited liver cell growth at higher concentrations. Blood levels after a 400 mg oral dose stay far below that range, but the gut lining is exposed to more, and there is no long-term human safety data.
Pregnancy and lactation: no safety data; avoid.
Allergy: some chrysin products are made from propolis, so people allergic to bee products should check the source.

Important Drug interactions

UGT1A1 substrates such as irinotecan: chrysin increases UGT1A1 in intestinal cells and has been given with irinotecan in a clinical study, so a gut-level interaction is plausible.
Aromatase inhibitor drugs (anastrozole, letrozole) and other hormone therapies: not studied together; ask your oncologist before taking chrysin.
Poor absorption does not rule out interactions, because much of the dose stays in the gut. If you take a medicine with a narrow safety margin, ask a pharmacist first.

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Frequently asked questions about Chrysin (5,7-Dihydroxyflavone)

What is chrysin used for?

Chrysin is a flavonoid found in passionflower, honey and propolis. It is marketed mainly as a testosterone or estrogen-balancing supplement because it blocks aromatase in lab tests, but those effects have not been shown in people.

Does chrysin boost testosterone?

The human evidence does not support it. Chrysin is very poorly absorbed when swallowed. Testosterone did not rise in the human studies, and in two randomized trials where 625 mg a day of chrysin was part of an androstenedione stack, estradiol went up rather than down.

How much chrysin should I take?

Labels often suggest 500 mg to a few grams a day, but no trial has shown a benefit at those doses, and absorption is very low. Piperine is sometimes added to improve absorption, but that has not been tested in people. A micellar form with quercetin and rutin about doubled blood levels in one trial.

Is chrysin safe?

Short-term use appears well tolerated: in a 30-day study of 15 people taking a chrysin, quercetin and rutin product, there were no clinically relevant safety changes. Chrysin was mutagenic in human liver cells and a bacterial test in the lab, at concentrations far above blood levels from a capsule. There is no long-term human safety data, and anyone with a hormone-sensitive condition should check with a doctor first.

What is Chrysin?

Chrysin is a flavone found in honey, propolis and some plants, including passionflower and Oroxylum indicum. It is sold mainly as a testosterone booster, on the idea that it blocks aromatase, the enzyme that turns testosterone into estrogen. That effect shows up in cell studies but has not held up in people.

Does Chrysin interact with any medications?

Possible interactions include: UGT1A1 substrates such as irinotecan: chrysin increases UGT1A1 in intestinal cells and has been given with irinotecan in a clinical study, so a gut-level interaction is plausible. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Chrysin?

NutraSmarts rates the evidence for Chrysin as Preliminary (1 out of 5). It is backed by 3 study summaries and 9 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(9 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. Gambelunghe C, Rossi R, Sommavilla M, Ferranti C, Rossi R, Ciculi C, Gizzi S, Micheletti A, Rufini S. Effects of chrysin on urinary testosterone levels in human males. J Med Food. 2003;6(4):387-90. doi: 10.1089/109662003772519967.PubMedUsed to support: Controlled human study in healthy men given daily propolis and honey, both natural chrysin sources, for 21 days, with urinary testosterone measured by GC/MS at baseline and days 7, 14 and 21 against a control group. Testosterone did not change at any time point. The authors concluded that these foods at the doses usually taken as supplements do not affect testosterone balance in men. A 2020 systematic review describes the study as 20 men aged 25 to 30 (10 per group) taking 1,280 mg of propolis tablets plus honey daily; the chrysin dose delivered is not stated.
  2. Walle T, Otake Y, Brubaker JA, Walle UK, Halushka PV. Disposition and metabolism of the flavonoid chrysin in normal volunteers. Br J Clin Pharmacol. 2001;51(2):143-6. doi: 10.1111/j.1365-2125.2001.01317.x.PubMedUsed to support: Pharmacokinetic study in seven healthy volunteers given a single oral 400 mg dose of chrysin. Peak plasma chrysin was 3 to 16 ng/mL with an AUC of 5 to 193 ng/mL/h, plasma chrysin sulfate was about 30 times higher, urine carried 0.2 to 3.1 mg of chrysin and 2 to 26 mg of chrysin glucuronide, and most of the dose was recovered in the feces as unchanged chrysin. The authors concluded that oral chrysin has low bioavailability, driven by extensive metabolism and efflux of metabolites back into the intestine. This measures blood levels, not any health outcome.
  3. Tobin PJ, Beale P, Noney L, Liddell S, Rivory LP, Clarke S. A pilot study on the safety of combining chrysin, a non-absorbable inducer of UGT1A1, and irinotecan (CPT-11) to treat metastatic colorectal cancer. Cancer Chemother Pharmacol. 2006;57(3):309-16. doi: 10.1007/s00280-005-0053-0.PubMedUsed to support: Uncontrolled pilot safety study in 20 patients with previously treated advanced colorectal cancer, who took oral chrysin twice daily for one week before and one week after each irinotecan infusion (350 mg/m2 every 3 weeks). There was no randomization and no control group, so diarrhea prevention was not tested. No toxicity was attributed to chrysin; delayed diarrhea was mild with 10 percent of patients reaching grade 3; grade 3 or 4 neutropenia occurred in 25 percent; and the plasma SN-38G to SN-38 ratio was very similar to historical controls. The authors concluded the combination may be safe and potentially useful and that a randomized trial is needed.
  4. Brown GA, Vukovich MD, Reifenrath TA, Uhl NL, Parsons KA, Sharp RL, King DS. Effects of anabolic precursors on serum testosterone concentrations and adaptations to resistance training in young men. Int J Sport Nutr Exerc Metab. 2000;10(3):340-59. doi: 10.1123/ijsnem.10.3.340.PubMedUsed to support: Randomized placebo-controlled trial in 20 young men who resistance-trained for 8 weeks while taking either placebo or a supplement providing 625 mg/day of chrysin alongside 300 mg androstenedione, 150 mg DHEA, 750 mg Tribulus terrestris, 300 mg indole-3-carbinol and 540 mg saw palmetto. The herbal extracts, chrysin among them, were added to reduce conversion of androgens to estrogens. Free and total testosterone were unchanged in both groups, while serum estradiol rose at weeks 2, 5 and 8 and estrone rose at weeks 5 and 8 in the supplement group. Strength gains were the same as placebo. The authors concluded that adding these herbal extracts to androstenedione does not raise testosterone, does not reduce the estrogenic effect of androstenedione, and does not augment training adaptations. Chrysin was one component of a multi-ingredient product, so its individual contribution cannot be isolated.
  5. Brown GA, Vukovich MD, Martini ER, Kohut ML, Franke WD, Jackson DA, King DS. Effects of androstenedione-herbal supplementation on serum sex hormone concentrations in 30- to 59-year-old men. Int J Vitam Nutr Res. 2001;71(5):293-301. doi: 10.1024/0300-9831.71.5.293.PubMedUsed to support: Randomized placebo-controlled trial in 55 healthy men aged 30 to 59 (28 supplement, 27 placebo) taking 625 mg/day of chrysin as part of a stack with 300 mg androstenedione, 150 mg DHEA, 540 mg saw palmetto, 300 mg indole-3-carbinol and 750 mg Tribulus terrestris for 28 days. The stated purpose of the herbal components was to prevent formation of estrogens and dihydrotestosterone from the ingested androgens. Total testosterone and PSA were unchanged. Androstenedione rose 342 percent, free testosterone 38 percent, dihydrotestosterone 71 percent and estradiol 103 percent, and HDL cholesterol fell by 5.0 mg/dL. The authors concluded the herbal products did not prevent conversion of ingested androstenedione to estradiol and dihydrotestosterone. Chrysin was one ingredient among several, so its separate effect cannot be isolated, including for the fall in HDL cholesterol.
  6. Balam FH, Ahmadi ZS, Ghorbani A. Inhibitory effect of chrysin on estrogen biosynthesis by suppression of enzyme aromatase (CYP19): A systematic review. Heliyon. 2020;6(3):e03557. doi: 10.1016/j.heliyon.2020.e03557.PubMedUsed to support: Systematic review of chrysin and aromatase activity. From 1,721 records screened, 20 articles were included: 17 in vitro, 2 in rats and 1 in humans. All but one found chrysin inhibited aromatase, and the authors concluded chrysin has aromatase-inhibiting potency. The single human study (Gambelunghe 2003: 20 men aged 25 to 30 given 1,280 mg of propolis tablets and honey daily for 21 days) found no change in urinary testosterone. The review does not show that swallowed chrysin changes hormone levels in people.
  7. Ibi A, Chang C, Kuo YC, Zhang Y, Do P, Du M, Roh YS, Gahler R, Hardy M, Solnier J. Comparative Pharmacokinetics and Safety of a Micellar Chrysin-Quercetin-Rutin Formulation: A Randomized Crossover Trial. Antioxidants (Basel). 2025;14(11):1313. doi: 10.3390/antiox14111313.PubMedUsed to support: Randomized double-blind three-period crossover trial in 16 healthy adults comparing a single oral dose of a micellar chrysin formulation co-encapsulated with quercetin and rutin against a non-micellar chrysin formulation and unformulated chrysin, with a 7-day washout and plasma chrysin measured over 24 hours. The micellar form gave more than 2-fold higher exposure than unformulated chrysin (AUC0-24 914.8 plus or minus 697.5 ng h/mL; Cmax 87.3 plus or minus 59.4 ng/mL) and more than 2.6-fold higher than the non-micellar form. A separate uncontrolled 30-day arm in 15 participants found daily use well tolerated with only mild reversible adverse events, and reported small reductions in fasting glucose. This trial measured blood levels and tolerability, not any clinical benefit, and the product tested contained quercetin and rutin as well as chrysin. The work was carried out by staff of ISURA, a co-author owns the Factors Group of companies, and a patent is pending on the LipoMicel delivery matrix.
  8. Oliveira GA, Ferraz ER, Souza AO, Lourenço RA, Oliveira DP, Dorta DJ. Evaluation of the mutagenic activity of chrysin, a flavonoid inhibitor of the aromatization process. J Toxicol Environ Health A. 2012;75(16-17):1000-11. doi: 10.1080/15287394.2012.696517.PubMedUsed to support: Laboratory genotoxicity study. Chrysin produced mutagenic activity in the micronucleus test in human HepG2 liver cells from 1 to 15 micromolar and gave a positive response in the Salmonella TA100 strain both with and without S9 metabolic activation, indicating base-pair substitution. It also inhibited HepG2 growth, by 83 percent at 50 micromolar after 24 hours and 97 percent after 48 hours. The authors concluded chrysin is mutagenic and cytotoxic in these systems and that the risk-benefit relationship of flavonoids at realistic exposures needs evaluating. This is cell culture and bacteria, not people, and measured human plasma chrysin after a 400 mg oral dose sits around 0.01 to 0.06 micromolar, below the active range in these assays.
  9. Walle T, Ta N, Kawamori T, Wen X, Tsuji PA, Walle UK. Cancer chemopreventive properties of orally bioavailable flavonoids--methylated versus unmethylated flavones. Biochem Pharmacol. 2007;73(9):1288-96. doi: 10.1016/j.bcp.2006.12.028.PubMedUsed to support: Preclinical study, no human participants. In human oral SCC-9 cancer cells, 5,7-dimethoxyflavone and 5,7,4'-trimethoxyflavone were about 10 times more potent inhibitors of cell proliferation (IC50 5 to 8 micromolar) than the unmethylated analogs chrysin and apigenin, and arrested cells in a different phase of the cell cycle. In rats, 5,7-dimethoxyflavone was well absorbed and accumulated in tissue while chrysin was not. This is the source for the claim that methylated flavone analogs overcome chrysin's absorption problem, and that work is entirely in cell lines and rats. It says nothing about what chrysin itself does in a person.