Home Ingredients CyanthOx™ (Sea Buckthorn Proanthocyanidin Extract)

CyanthOx™ (Sea Buckthorn Proanthocyanidin Extract)

Hippophae rhamnoides L.
Evidence Level
Preliminary
1 Clinical Trial
5 Documented Benefits
1/5 Evidence Score

CyanthOx™ is a water-soluble proanthocyanidin extract of sea buckthorn (Hippophae rhamnoides) berries made by Puredia, which says its sea buckthorn is grown on the Tibetan Plateau. Grades are standardized to at least 30%, 50% or 80% proanthocyanidins. The only human study gave 12 healthy adults one 500 mg dose of CyanthOx 30 or placebo and counted stem cells in the blood over 2 hours. Counts rose from baseline, but the fixed time point comparisons with placebo were not significant; only an added peak response analysis was positive. A company led by the lead author co-sponsored the study. The other studies of the extract are cell and mouse studies with Puredia staff as authors. The maker also cites a high ORAC value, a test-tube measure whose federal database the USDA removed in 2012. For sea buckthorn oil, juice and berries, see the separate Sea Buckthorn entry.

Studied Dose 500 mg of CyanthOx 30 (150 mg proanthocyanidins, per the maker) as a single dose in the only human study. The maker lists 500, 300 or 187.5 mg a day depending on grade. No repeated-dose trial has been published.
Active Compound Proanthocyanidins (at least 30%, 50% or 80% by grade, per the maker) and bioflavonoids (at least 20%, including quercetin and kaempferol). A Puredia-affiliated study described the extract as mainly epicatechin gallate, B-type proanthocyanidins, and gallocatechin-catechin and gallocatechin dimers.

Benefits

Circulating stem cell counts after a single dose

In a placebo-controlled crossover in 12 healthy adults, one 500 mg dose raised some blood stem cell counts from baseline within 2 hours, but the paper's figures show no significant difference from placebo at the fixed time points. A positive result came only from an added analysis of each person's peak response. The study was co-sponsored by a company led by its lead author, and no health outcome was measured.

Supported by Trial 1

Antioxidant activity in cell studies

In cell culture studies by Puredia-affiliated authors, the extract reduced hydrogen peroxide damage in macrophages and retinal cells. The maker cites an ORAC value about 9 times that of grape seed extract. ORAC is a test-tube measure, and the USDA removed its ORAC database in 2012, saying such values have no relevance to effects on human health. No human antioxidant outcome has been tested.

Supported by Trial 1

Skin and blood vessel cell effects in lab and mouse studies

In a study by Puredia-affiliated authors, sea buckthorn proanthocyanidins given by mouth to mice with chemically induced aging improved skin aging measures and raised total antioxidant capacity. In cultured blood vessel lining cells, they reduced damage from palmitic acid. No human skin or circulation trial of CyanthOx has been published.

Supported by Trial 1

Proanthocyanidin makeup of sea buckthorn extracts

A review describes sea buckthorn proanthocyanidins as built mainly from gallocatechin and epigallocatechin units (prodelphinidins), which sets them apart from grape seed proanthocyanidins. A Puredia-affiliated analysis found the maker's extract to be mainly epicatechin gallate and dimers built from catechin and gallocatechin units. Whether this changes absorption or effects in people has not been tested.

Supported by Trial 1

A different fraction from sea buckthorn oil and juice

CyanthOx is a water-soluble polyphenol extract, not the oil or the whole berry. Human trials of sea buckthorn oil, berries, juice, puree and a hydroethanolic fruit extract, described in the separate Sea Buckthorn entry, studied other products, and their results do not transfer to this extract.

Supported by Trial 1

Mechanism of action

1

Proanthocyanidin structure

Proanthocyanidins are chains of flavan-3-ol units. Sea buckthorn proanthocyanidins are built from catechin, epicatechin, gallocatechin and epigallocatechin units linked by B-type bonds; gallocatechin units carry an extra hydroxyl group and form prodelphinidins. The maker's extract also contains flavonols such as quercetin and kaempferol.

2

Nrf2 and mitochondrial pathways in cells

In macrophages exposed to hydrogen peroxide, the extract raised mitochondrial membrane potential and activated the AMPK, PGC-1α and Nrf2 pathway. In retinal pigment cells, it activated Nrf2 and HO-1 signaling and restored superoxide dismutase activity. These were cell studies with Puredia-affiliated authors, at concentrations not shown to occur after an oral dose.

3

Stem cell release hypothesis

The authors of the human study proposed that the extract releases stem cells from bone marrow into the blood. This was inferred from blood counts over 2 hours; no mechanism was tested, the fixed time point comparisons with placebo were not significant, and the result has not been repeated by an independent group.

4

Absorption of oligomers versus polymers

A review of sea buckthorn proanthocyanidins notes that human absorption data for its oligomers versus polymers are scarce and that, from the wider proanthocyanidin literature, smaller oligomers are thought to be better absorbed than polymers. How much of CyanthOx reaches the blood has not been measured.

Clinical trials

1
Single 500 mg dose and circulating stem cells in healthy adults
PubMed

Randomized, double-blind, placebo-controlled crossover with visits at least 1 week apart: one 500 mg capsule of a Puredia sea buckthorn berry proanthocyanidin extract (identified by Puredia as CyanthOx 30) or rice flour placebo, with blood drawn at baseline, 1 hour and 2 hours. Co-sponsored by Biomx StemCeuticals, whose co-founder was the lead author, and NIS Labs, whose research director was a co-author and which ran the study. The registry entry (NCT03388073) also lists 250 mg and berry blend arms that the paper does not report. (Drapeau et al. 2019, Clin Interv Aging)

12 healthy adults (8 women, 4 men) aged 28 to 70.

At the fixed 1 and 2 hour time points, the paper's figures report no significant difference from placebo for CD45dim CD34+ CD309 negative progenitor cells (P<0.17), CD31+ endothelial cells or CD90+ cells, although the text reports P<0.04 and P<0.05 for endothelial cells. Progenitor cells rose from baseline at 2 hours. An added analysis of each person's peak response, adjusted for placebo, reported rises of about 20% to 33%. Adverse events were not reported.

Side effects and drug interactions

Common Potential side effects

The only human study gave a single 500 mg dose to 12 healthy adults and did not report adverse events, so there is no repeated-dose safety data for this extract.
The study excluded people with known allergies to berry products.
Pregnancy and breastfeeding: no safety data exist for this concentrated extract.

Important Drug interactions

Anticoagulant and antiplatelet drugs (such as warfarin): in test-tube work, an extract of sea buckthorn seeds, a different plant part, slowed white thrombus formation. No human data exist for this berry extract, so this is a precautionary note; ask a clinician before combining.
Iron supplements: in human absorption studies, polyphenol-containing drinks cut iron absorption from a bread meal by about 50% to 90%. This extract was not tested, but taking iron at a different time is a reasonable precaution.

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Frequently asked questions about CyanthOx™ (Sea Buckthorn Proanthocyanidin Extract)

What is CyanthOx used for?

CyanthOx is a sea buckthorn berry proanthocyanidin extract that Puredia markets as an antioxidant and for stem cell support. The only human study gave 12 healthy adults a single 500 mg dose; blood stem cell counts rose from baseline, but the comparisons with placebo at fixed time points were not significant. Its other evidence comes from cell and mouse studies, so no benefit in people has been shown.

What is the recommended dosage of CyanthOx?

There is no established dose. The human study used one 500 mg dose of CyanthOx 30, which the maker says supplies 150 mg proanthocyanidins. Puredia lists 500, 300 or 187.5 mg a day depending on grade. No study has tested daily use.

Is CyanthOx safe, and does it have side effects?

There is little safety data. The only human study gave one dose to 12 healthy adults and did not report adverse events, and no repeated-dose study exists. There are no data for pregnancy or breastfeeding. Because polyphenols can reduce iron absorption, and a sea buckthorn seed extract affected clot formation in a test tube, people taking iron or blood thinners should ask a clinician first.

How is CyanthOx different from sea buckthorn oil?

CyanthOx is a water-soluble polyphenol extract of the berry. Sea buckthorn oil is a fat-soluble product rich in fatty acids. The oil, berries and juice have their own human trials, described in the Sea Buckthorn entry, and those results do not apply to this extract.

What is CyanthOx?

CyanthOx™ is a water-soluble proanthocyanidin extract of sea buckthorn (Hippophae rhamnoides) berries made by Puredia, which says its sea buckthorn is grown on the Tibetan Plateau. Grades are standardized to at least 30%, 50% or 80% proanthocyanidins.

Does CyanthOx interact with any medications?

Possible interactions include: Anticoagulant and antiplatelet drugs (such as warfarin): in test-tube work, an extract of sea buckthorn seeds, a different plant part, slowed white thrombus formation. No human data exist for this berry extract, so this is a precautionary note; ask a clinician before combining. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for CyanthOx?

NutraSmarts rates the evidence for CyanthOx as Preliminary (1 out of 5). It is backed by 1 study summary and 12 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(12 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. Drapeau C, Benson KF, Jensen GS. Rapid and selective mobilization of specific stem cell types after consumption of a polyphenol-rich extract from sea buckthorn berries (Hippophae) in healthy human subjects. Clin Interv Aging. 2019;14:253-263. doi: 10.2147/CIA.S186893.PubMedUsed to support: The only human study of the extract: a randomized, double-blind, placebo-controlled crossover in 12 healthy adults given one 500 mg dose of a Puredia sea buckthorn berry proanthocyanidin extract (Puredia identifies it as CyanthOx 30) or rice flour placebo, with blood drawn at 0, 1 and 2 hours. CD45dim CD34+ CD309 negative progenitor cells rose from baseline at 2 hours (P<0.007), but the difference from placebo was not significant (P<0.17); the figure legends also report no significant between-treatment difference for endothelial and CD90+ cells, although the text gives P<0.04 and P<0.05 for endothelial cells. A post hoc analysis of each person's peak response, adjusted for placebo, reported significant rises. Adverse events were not reported. Co-sponsored by Biomx StemCeuticals and NIS Labs; the lead author is co-founder and executive director of Biomx StemCeuticals and a co-author is research director of NIS Labs, which ran the study. Blood stem cell counts are a laboratory measure, not a health outcome.
  2. Zhou Z, He Z, He Y, Peng Q. From Desert Greening to Human Health: A Systematic Review of the Extraction, Unique Structure, and Bioactivity of Sea Buckthorn Proanthocyanidins. Foods. 2025;14(18):3203. doi: 10.3390/foods14183203.PubMedUsed to support: Review of extraction methods, structure and laboratory bioactivity of sea buckthorn proanthocyanidins. It describes them as built mainly from (epi)gallocatechin units with B-type links, setting them apart from grape seed proanthocyanidins; tabulated seed fractions had about 81% to 84% prodelphinidins, and a Qinghai berry powder extract was mostly dimers. It notes that human bioavailability data for sea buckthorn proanthocyanidin oligomers versus polymers are scarce. It contains no human outcome trials. All authors are at Northwest A&F University and declare no conflicts; the senior author is also senior author of the Puredia-affiliated studies cited here.
  3. Zhu Y, Yuen M, Li W, Yuen H, Wang M, Smith D, Peng Q. Composition analysis and antioxidant activity evaluation of a high purity oligomeric procyanidin prepared from sea buckthorn by a green method. Curr Res Food Sci. 2021;4:840-851. doi: 10.1016/j.crfs.2021.11.008.PubMedUsed to support: Laboratory study: a sea buckthorn procyanidin made from Puredia sea buckthorn powder at 91.5% purity was mainly (-)-epicatechin gallate, procyanidin B, gallocatechin-catechin and gallocatechin dimers, scavenged free radicals in test-tube assays, and protected RAW264.7 cells from hydrogen peroxide. Three authors list Puredia Limited as their affiliation, although the paper declares no competing interests. Chemistry and cell evidence only.
  4. Ma K, Yuen M, Yuen T, Yuen H, Peng Q. Protective Mechanism of Sea buckthorn Proanthocyanidins Against Hydrogen Peroxide-Introduced Oxidative Damage in Adult Retinal Pigment Epithelial-19. Antioxidants (Basel). 2024;13(11):1352. doi: 10.3390/antiox13111352.PubMedUsed to support: Cell study: sea buckthorn proanthocyanidins (100 μg/mL worked best) reduced malondialdehyde and reactive oxygen species, restored superoxide dismutase and glutathione, and activated Nrf2/HO-1 signaling in ARPE-19 retinal cells damaged by hydrogen peroxide. Three of five authors were employed by Puredia Limited (disclosed). Cells were exposed directly; this does not show what reaches the eye after an oral dose.
  5. Liu X, Yuen M, Yuen T, Yuen H, Wang M, Peng Q. Anti-skin aging effect of sea buckthorn proanthocyanidins in D-galactose-induced aging mice. Food Sci Nutr. 2024;12(2):1082-1094. doi: 10.1002/fsn3.3823.PubMedUsed to support: Mouse study: in mice aged with D-galactose injections, sea buckthorn proanthocyanidins given by gavage at 25, 50 and 100 mg/kg reduced skin aging changes and raised total antioxidant capacity. Three authors were from Puredia Limited. A chemically induced aging model; no human skin trial of the extract has been published.
  6. Sławińska N, Żuchowski J, Stochmal A, Olas B. Extract from Sea Buckthorn Seeds-A Phytochemical, Antioxidant, and Hemostasis Study; Effect of Thermal Processing on Its Chemical Content and Biological Activity In Vitro. Nutrients. 2023;15(3):686. doi: 10.3390/nu15030686.PubMedUsed to support: Independent in vitro study of extracts from raw and roasted sea buckthorn seeds, a different plant part from this berry extract. Both reduced lipid peroxidation and protein carbonylation in human plasma; neither changed coagulation times, but the roasted seed extract at 50 μg/mL prolonged white thrombus formation. Basis for the precautionary anticoagulant note only; not evidence about CyanthOx.
  7. Liu K, Li W, Yuen M, Yuen T, Yuen H, Wang M, Peng Q. Sea Buckthorn Proanthocyanidins are the Protective Agent of Mitochondrial Function in Macrophages Under Oxidative Stress. Front Pharmacol. 2022;13:914146. doi: 10.3389/fphar.2022.914146.PubMedUsed to support: Cell study of the product: the methods state the extract was supplied by Puredia, made by water extraction and resin chromatography, and trademarked as CyanthOx. RAW264.7 macrophages pretreated with 25, 50 or 100 μg/mL and then exposed to 800 μmol/L hydrogen peroxide showed higher mitochondrial membrane potential, less mitochondrial swelling, and activation of the AMPK-PGC1α-Nrf2 pathway. Four of seven authors were employed by Puredia Limited (disclosed). Not human evidence.
  8. Lin X, Yuen M, Yuen T, Yuen H, Wang M, Peng Q. Regulatory Effect of Sea-Buckthorn Procyanidins on Oxidative Injury HUVECs. Front Nutr. 2022;9:850076. doi: 10.3389/fnut.2022.850076.PubMedUsed to support: Cell study: in human umbilical vein endothelial cells damaged by palmitic acid, sea buckthorn procyanidins raised mitochondrial membrane potential and nitric oxide and reduced LDH leakage, probably through p38MAPK/NF-κB signaling. Three authors were employed by Puredia Limited (disclosed). Not human evidence.
  9. Hurrell RF, Reddy M, Cook JD. Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. Br J Nutr. 1999;81(4):289-95. doi: 10.1017/S0007114599000537.PubMedUsed to support: Human radio-iron absorption study: compared with water, drinks containing 20 to 50 mg total polyphenols per serving cut iron absorption from a bread meal by 50% to 70%, and drinks with 100 to 400 mg by 60% to 90%. Basis for the iron timing precaution; sea buckthorn extract was not tested. The DOI was confirmed through Crossref because the PubMed record lists only the publisher item identifier.
  10. Natural Immune Systems Inc. Evaluation of Plant-based Nutritional Products on Stem Cells (NCT03388073). ClinicalTrials.gov. 2018;First posted 2018-01-02; last updated 2019-03-13; status unknown..SourceUsed to support: Not PubMed-indexed; registry record read through the ClinicalTrials.gov API (accessed 2026). Sponsored by Natural Immune Systems Inc (NIS Labs). It lists four arms: sea buckthorn berry proanthocyanidin extract 250 mg, the same extract 500 mg, a sea buckthorn blend with other berry extracts, and placebo, each as a single dose, with changes in blood stem cell counts at 1 and 2 hours as outcomes. The published paper (Drapeau 2019) reports only the 500 mg and placebo arms.
  11. Puredia. CyanthOx™ product page. Puredia (manufacturer website). 2026;Accessed 2026-10-25..SourceUsed to support: Not PubMed-indexed; manufacturer page. Lists grades with proanthocyanidins at least 30%, 50% or 80% and bioflavonoids at least 20%, describes a water-soluble sea buckthorn extract, gives daily amounts of 500, 300 or 187.5 mg depending on grade, states that the clinical study used 500 mg of CyanthOx 30 containing 150 mg proanthocyanidins, cites the Liu 2022 macrophage study as using CyanthOx 80, and gives a company-tested ORAC value of 895,281 μmol TE/100 g, which it says is about 9 times grape seed extract and about 2 times French maritime pine bark extract. These are the maker's own claims.
  12. Daniells S. ORAC has 'ongoing value', says expert, as USDA removes online database. NutraIngredients. 2012;Published 2012-06-13..SourceUsed to support: Not PubMed-indexed; trade news report. The USDA Nutrient Data Laboratory removed its ORAC Database for Selected Foods, stating that antioxidant capacity values have no relevance to the effects of specific bioactive compounds, including polyphenols, on human health, and that ORAC values were routinely misused by food and supplement companies to promote their products.