Chrysin

Also called 5,7-dihydroxyflavone, chrysin flavone, micellar chrysin.

Best grade D across 3 graded outcomes Other Last checked

The short answer

From 9 sources

Chrysin is a flavone found in honey and propolis, marketed to block testosterone's conversion to estrogen. It inhibits aromatase in lab tests, but swallowed chrysin is poorly absorbed: 400 mg gave peak blood levels of only 3–16 ng/mL. No trial has tested chrysin alone for hormones or performance, and three placebo-controlled trials of blends with 300–625 mg did not stop estrogen rising (grade D).

Every graded outcome on this page

3 rows · line = participants
  1. Grade DEstrogen and DHT formation (androstenedione blend with 625 mg chrysin)Testosterone and estrogenn 55
  2. Grade DEstrogen and DHT formation (androstenediol blend with 300 mg chrysin)Testosterone and estrogenn 55
  3. Grade DTestosterone, estrogens and strength gains (blend with 625 mg chrysin)Testosterone and estrogenn 20

Key facts

What it is
5,7-dihydroxyflavone, a flavone found in many plants, honey and propolis9
Lab finding
Potent competitive inhibitor of aromatase in human placental and ovarian microsomes7
Absorption
A 400 mg dose gave peak plasma chrysin of 3–16 ng/mL; most of the dose came out in faeces4
Trials of chrysin alone
None for testosterone, estrogen or performance; the controlled trials tested multi-ingredient androgen blends123
Blend results
With 300–625 mg chrysin in the blends, estradiol still rose 86–103% in men aged 30–5923

What it is

Chrysin is a flavone found in honey and propolis, sold as a natural aromatase inhibitor for testosterone.

How it works

Proposed

In human placental and ovarian tissue preparations, chrysin competitively inhibited aromatase, the enzyme that turns androgens into estrogens. No human study has shown aromatase inhibition from swallowed chrysin; its poor oral absorption may be one reason.74

Forms, side by side

2 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.

Chrysin forms compared

2 forms
Chrysin forms compared: 2 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
2 formsPlain chrysin powder or capsulesMicellar chrysin with quercetin and rutin (LipoMicel)
Absorption in peopleLow: after 400 mg, peak plasma chrysin was 3–16 ng/mL and chrysin sulfate levels were about 30-fold higher; most of the dose was excreted in faeces.4More than 2-fold higher 24-hour exposure than unformulated chrysin in a 16-person crossover trial.5
GI toleranceNo toxicity attributable to chrysin was seen in a 20-patient pilot; the absorption study abstract does not report side effects.64Mild, reversible adverse events and no clinically relevant lab changes over 30 days of daily use (15 people).5
Studied forAbsorption studies; blended into androgen supplementsAbsorption and short-term safety
  1. Plain chrysin powder or capsules
    Absorption in people
    Low: after 400 mg, peak plasma chrysin was 3–16 ng/mL and chrysin sulfate levels were about 30-fold higher; most of the dose was excreted in faeces.4
    GI tolerance
    No toxicity attributable to chrysin was seen in a 20-patient pilot; the absorption study abstract does not report side effects.64
    Studied for
    Absorption studies; blended into androgen supplements
  2. Micellar chrysin with quercetin and rutin (LipoMicel)
    Absorption in people
    More than 2-fold higher 24-hour exposure than unformulated chrysin in a 16-person crossover trial.5
    GI tolerance
    Mild, reversible adverse events and no clinically relevant lab changes over 30 days of daily use (15 people).5
    Studied for
    Absorption and short-term safety
Every cell holds data from a cited page; citation numbers link to the page that holds them.Scroll the table for every column

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

3 graded outcomes, largest study first

All 3 graded outcomes found no effect. The largest, a 2001 randomized trial of 55 people on estrogen and DHT formation (androstenediol blend with 300 mg chrysin), found no effect.

Bar: the ages a study enrolled (running to the edge when it states no upper or lower limit). Dot: only a mean age, counted as near your age within 5 years. Tick: the mean age inside a range.

3Testosterone, estrogens and strength gains (blend with 625 mg chrysin): no effect, mean age 23

1Estrogen and DHT formation (androstenediol blend with 300 mg chrysin): no effect, 30–58

2Estrogen and DHT formation (androstenedione blend with 625 mg chrysin): no effect, 30–59

1. Estrogen and DHT formation (androstenediol blend with 300 mg chrysin): no effect, 55 people12. Estrogen and DHT formation (androstenedione blend with 625 mg chrysin): no effect, 55 people23. Testosterone, estrogens and strength gains (blend with 625 mg chrysin): no effect, 20 people3

1Estrogen and DHT formation (androstenediol blend with 300 mg chrysin)

No effect · Grade D · RCT, 55 people, 2001

Healthy men aged 30–58 (USA)

Dose, result and source
Every graded outcome on this page, largest study first
OutcomeFoundPeopleStudyWho was studied
Estrogen and DHT formation (androstenediol blend with 300 mg chrysin)No effect55Grade D · RCT, 2001Healthy men aged 30–58 (USA)
Estrogen and DHT formation (androstenedione blend with 625 mg chrysin)No effect55Grade D · RCT, 2001Healthy men aged 30–59 (USA)
Testosterone, estrogens and strength gains (blend with 625 mg chrysin)No effect20Grade D · RCT, 2000Young men doing 3 days a week of resistance training (USA)
Each circle is one graded outcome on this page, numbered from the largest study down, and placed by how many people it studied (log scale). By age shows the ages each study enrolled, where it states them. It shows who was studied and what was found, not advice about your dose.

Every graded row

3 rows
Grade DEstrogen and DHT formation (androstenedione blend with 625 mg chrysin)Testosterone and estrogenEstradiol +103%RCT
n 55 · 2001

No effect Total testosterone was unchanged; estradiol rose 103%, DHT 71% and free testosterone 38%, and HDL cholesterol fell 5.0 mg/dL. The herbs did not prevent conversion to estradiol and DHT.

Design
RCT, n = 55, 2001
Population
Healthy men aged 30–59 (USA)
Form
Blend: androstenedione 300 mg, DHEA 150 mg, saw palmetto 540 mg, indole-3-carbinol 300 mg, chrysin 625 mg, Tribulus 750 mg
Dose
625 mg chrysin/day within the blend
Duration
28 days
Source
Reference 2 · PubMed 11725694 (opens PubMed)
Grade DEstrogen and DHT formation (androstenediol blend with 300 mg chrysin)Testosterone and estrogenEstradiol +86%RCT
n 55 · 2001

No effect Total testosterone was unchanged; estradiol rose 86%, DHT 57% and free testosterone 37%, and HDL cholesterol fell 0.14 mmol/L. The herbs did not prevent estradiol or DHT formation.

Design
RCT, n = 55, 2001
Population
Healthy men aged 30–58 (USA)
Form
Blend: androstenediol 300 mg, saw palmetto 480 mg, indole-3-carbinol 450 mg, chrysin 300 mg, gamma-linolenic acid 1,500 mg, Tribulus 1,350 mg
Dose
300 mg chrysin/day within the blend
Duration
28 days
Source
Reference 3 · PubMed 11601567 (opens PubMed)
Grade DTestosterone, estrogens and strength gains (blend with 625 mg chrysin)Testosterone and estrogenNo effectRCT
n 20 · 2000

No effect Free and total testosterone did not change; estradiol and estrone rose with the blend, and strength gains matched placebo. The herbs did not stop androstenedione being converted to estrogen.

Design
RCT, n = 20, 2000
Population
Young men doing 3 days a week of resistance training (USA)
Form
Blend: androstenedione 300 mg, DHEA 150 mg, Tribulus 750 mg, chrysin 625 mg, indole-3-carbinol 300 mg, saw palmetto 540 mg
Dose
625 mg chrysin/day within the blend (on 6 of the 8 weeks)
Duration
8 weeks
Source
Reference 1 · PubMed 10997957 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

Lab potency vs blood levels

Chrysin was second only to 7,8-benzoflavone among the flavones tested against aromatase in 1984, but 400 mg by mouth produced peak blood levels of only 3–16 ng/mL.74

How we got this: 1984 aromatase study and 2001 absorption study abstracts

Estrogen kept rising

Across three placebo-controlled blend trials, estrogen markers rose despite 300–625 mg of chrysin, the very change chrysin is marketed to stop.123

How we got this: Evidence table on this page

Industry-run absorption data

The micellar chrysin trial was run by staff of ISURA, with the owner of the Factors Group among the authors and a patent pending on the formula.5

How we got this: Conflict-of-interest statement in the PubMed record

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from 300 to 625 mg/day of chrysin inside androgen-precursor blends for 4 to 8 weeks, plus single 400 mg doses in an absorption study. No trial has tested chrysin alone for an outcome.1234

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

What Chrysin meets

1 cited row 12 tested together

Medicines 1

Chrysin1 medicine · 5 supplements

Supplements and foods 5

  • Measured in a human study
  • Tested together in a graded trial
Also cited: 12 tested together

  1. Irinotecan and other UGT1A1 substrates

    • PK studyMeasured in a human study

      Irinotecan and other UGT1A1 substrates, for example Irinotecan (CPT-11): Chrysin was given with irinotecan because cell studies showed it can induce the UGT1A1 enzyme; in a 20-patient pilot, the ratio of inactive to active irinotecan metabolite was similar to historical controls and no chrysin toxicity was seen.

      Source 6, Cancer Chemother Pharmacol (2006)

  2. DHEADHEA page

    • Tested together

      Testosterone, estrogens and strength gains (blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

    • Tested together

      Estrogen and DHT formation (androstenedione blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

  3. Indole-3-carbinolIndole-3-carbinol page

    • Tested together

      Testosterone, estrogens and strength gains (blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

    • Tested together

      Estrogen and DHT formation (androstenedione blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

    • Tested together

      Estrogen and DHT formation (androstenediol blend with 300 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

  4. Omega-6 Fatty AcidsOmega-6 Fatty Acids page

    • Tested together

      Estrogen and DHT formation (androstenediol blend with 300 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

  5. Saw palmettoSaw palmetto page

    • Tested together

      Testosterone, estrogens and strength gains (blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

    • Tested together

      Estrogen and DHT formation (androstenedione blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

    • Tested together

      Estrogen and DHT formation (androstenediol blend with 300 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

  6. Tribulus TerrestrisTribulus Terrestris page

    • Tested together

      Testosterone, estrogens and strength gains (blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

    • Tested together

      Estrogen and DHT formation (androstenedione blend with 625 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

    • Tested together

      Estrogen and DHT formation (androstenediol blend with 300 mg chrysin). Graded on the Chrysin page; tested together is not a claim that they work better together.

Rows as our evidence profiles cite them; links stay on this site. Line weight shows what backs a row, not how serious an interaction is. No line means none was found in our sources, not that a combination is safe. Not medical advice: ask your pharmacist.

Interactions

1 agent
Published interactions, grouped by kind
AgentWhat the source saysEvidence
Medicines1
Irinotecan and other UGT1A1 substratese.g. Irinotecan (CPT-11)Chrysin was given with irinotecan because cell studies showed it can induce the UGT1A1 enzyme; in a 20-patient pilot, the ratio of inactive to active irinotecan metabolite was similar to historical controls and no chrysin toxicity was seen.6PK study

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Chrysin and your picks, and between your picks.

Most cited:

Add a supplement or medicine you take to check it against Chrysin.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Not medical advice, and no dosing advice. An empty result means no row we cite names that pair, by name or through a drug class we can link the medicine to, not that a combination is safe. Where our sources name only a group of medicines we cannot match, the cabinet says so. Ask your pharmacist before you combine supplements and medicines.

Who should be careful

3 groups
People using hormone or chemotherapy drugs
Chrysin inhibits a steroid-converting enzyme in lab tests and has only pilot data alongside irinotecan; combinations with hormone therapy have not been studied.76
Pregnancy, breastfeeding and children
No reliable data: no cited study included pregnant or breastfeeding women or children, and neither LactMed nor LiverTox has a chrysin entry.145
Blends with steroid precursors
The only chrysin outcome trials used blends built around androstenedione or androstenediol, and in them estradiol and DHT rose and HDL cholesterol fell. In March 2004 FDA declared androstenedione supplements adulterated and sent warning letters to 23 companies, citing a possible risk of serious health problems from its conversion to active hormones. Avoid any chrysin product that also contains a steroid precursor.1238
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.

How to read the label

What to check on the Supplement Facts panel.

How to read the label

3 checks
Absorption is the bottleneck

Plain chrysin reaches blood only in nanogram amounts, so a large label dose does not mean a large blood level.4

Enhanced-absorption claims

One micellar formula roughly doubled exposure versus plain chrysin in an industry-linked trial; that still does not show any hormone effect.5

Blends hide the active ingredient

The only outcome trials used chrysin inside steroid-precursor blends, so their results cannot be credited to chrysin.123

Have the bottle? Photograph its Supplement Facts panel and see each line, chrysin included, beside the doses and forms the trials used in Label X-Ray.

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

5 answers
Does chrysin raise testosterone?

No trial has tested chrysin alone for testosterone. In three placebo-controlled trials of androgen blends containing 300–625 mg of chrysin, total testosterone did not change. Free testosterone rose 37–38% in the two 28-day trials, but those blends also contained androstenedione or androstenediol, steroid precursors the body converts to testosterone, so the rise cannot be credited to chrysin.123

Does chrysin block estrogen?

It inhibits aromatase in lab tests, but in men given blends with chrysin, estradiol still rose by 86–103%.723

Does micellar chrysin work better?

A micellar chrysin-quercetin-rutin formula gave more than twice the blood exposure of plain chrysin in 16 people. The trial was run by researchers tied to the formula (ISURA staff, the owner of the Factors Group and the patent's inventors) and measured absorption, not hormones.5

Is chrysin safe?

Short studies report no chrysin-related toxicity and only mild side effects over 30 days. Long-term human safety data are lacking.56

Why might chrysin not work when swallowed?

Absorption is very low: 400 mg produced peak blood chrysin of only 3–16 ng/mL, and most of the dose was found in faeces.4

Sources

9 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

9 sources
  1. 1Effects of anabolic precursors on serum testosterone concentrations and adaptations to resistance training in young men.RCT Int J Sport Nutr Exerc Metab, 2000 · PMID 10997957
  2. 2Effects of androstenedione-herbal supplementation on serum sex hormone concentrations in 30- to 59-year-old men.RCT Int J Vitam Nutr Res, 2001 · PMID 11725694
  3. 3Endocrine and lipid responses to chronic androstenediol-herbal supplementation in 30 to 58 year old men.RCT J Am Coll Nutr, 2001 · PMID 11601567
  4. 4Disposition and metabolism of the flavonoid chrysin in normal volunteers.PK study Br J Clin Pharmacol, 2001 · PMID 11259985
  5. 5Comparative Pharmacokinetics and Safety of a Micellar Chrysin-Quercetin-Rutin Formulation: A Randomized Crossover Trial.Crossover RCT Antioxidants (Basel), 2025 · PMID 41300470
  6. 6A pilot study on the safety of combining chrysin, a non-absorbable inducer of UGT1A1, and irinotecan (CPT-11) to treat metastatic colorectal cancer.Open-label trial Cancer Chemother Pharmacol, 2006 · PMID 16003560
  7. 7Inhibition of human estrogen synthetase (aromatase) by flavones.Animal study Science, 1984 · PMID 6474163
  8. 8"Adulterated" Androstenedione: What FDA's Action against Andro Means for IndustryReview J Int Soc Sports Nutr, 2004 · pmc.ncbi.nlm.nih.gov
  9. 9Chrysin: Sources, beneficial pharmacological activities, and molecular mechanism of action.Review Phytochemistry, 2018 · PMID 29161583

What changed

Every dated change to this page: what changed, who made it and why.

Change log

3 entries
Dated changes to this page
DateChangeWho and why
who should avoid, questions, relatedRe-checked against the audit standard. PubMed searches (chrysin human trials, pharmacokinetic and interaction studies, meta-analyses through 2026) found no new human outcome or interaction study beyond the nine sources already cited; LiverTox and LactMed have no chrysin entry and NCCIH and MedlinePlus have no chrysin page, so the interaction list stays at the irinotecan pilot. Pregnancy note now says plainly that there are no reliable data; added page questions and the performance goal hub.Writer: Kymata Health EditorialTrigger: A–Z audit against docs/supplements/AUDIT-STANDARD.md
allInitial editorial evidence review (first draft). Every PMID checked against NCBI E-utilities esummary (titles and years taken from the record; retraction, erratum and expression-of-concern links checked in the PubMed record) and the abstract read for each cited row. Studied doses are reported as research doses, not dosing advice. Thin evidence flagged: no outcome trial of chrysin alone; the controlled trials are multi-ingredient androgen-precursor blends. A 2003 honey-and-propolis urinary testosterone study was not used because its abstract gives no group sizes.Writer: Kymata Health EditorialTrigger: new page
allAdversarial review: summary and FAQ now say no trial tested chrysin alone for hormones or performance (absorption and safety studies did test it alone); the FAQ explains that the 37–38% free-testosterone rise came with androstenedione or androstenediol, not chrysin; 'older men' corrected to men aged 30–59; mechanism softened (no human study shows aromatase inhibition); the micellar trial's links (ISURA staff, Factors Group owner, patent inventors) stated instead of 'run by the maker'; the steroid-precursor safety entry now gives FDA's March 2004 action as described in source 8 (a commentary by industry-side lawyers critical of FDA) and says to avoid chrysin products that contain a steroid precursor.Writer: Kymata Health EditorialTrigger: review

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