8-Prenylnaringenin

8-Prenylnaringenin at a Glance

8-Prenylnaringenin — 8-PN, also called hopein — is a prenylated flavanone found in the lupulin glands of hops (Humulus lupulus). Structurally it is naringenin carrying a prenyl group at the 8-position, and it is biosynthetically tied to the hop chalcone xanthohumol and the flavanone isoxanthohumol.

Its defining property is estrogenic potency: 8-PN is the most potent phytoestrogen yet identified, binding both estrogen receptors more strongly than the soy isoflavone genistein or the classic phytoestrogen coumestrol ^{1,2Reference 1Milligan SR et al. · 1999Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beerView study →Reference 2Milligan SR et al. · 2000The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoidsView study →}. This single fact organises the whole molecule — it is the compound behind hops’ traditional use for menstrual and menopausal complaints and behind the old “hop-pickers’ menstrual” folklore, and it is why the safety headline for concentrated hop products is estrogenic rather than toxicological ^{17,18Reference 17Štulíková K et al. · 2018Therapeutic perspectives of 8-prenylnaringenin, a potent phytoestrogen from hopsView study →Reference 18Pohjanvirta R · 2022The potent phytoestrogen 8-prenylnaringenin: a friend or a foe? International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/35328588/View study →}.

The honest evidence posture: the isolated molecule has striking receptor pharmacology and a genuine (if small) human clinical footprint, but almost all of the positive human data come from 8-PN-standardised hop extracts delivering microgram doses, not from the pure compound, and 8-PN content swings widely by cultivar, storage and — crucially — by an individual’s gut flora ^{4,5,8Reference 4Possemiers S et al. · 2005Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringeninView study →Reference 5Possemiers S et al. · 2006In vitroThe prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestineView study →Reference 8Heyerick A et al. · 2006RCTA first prospective, randomized, double-blind, placebo-controlled study on the use of a standardized hop extract to alleviate menopausal discomfortsView study →}. Intrinsic toxicity is low; the caution is hormonal.

The Most Potent Phytoestrogen Known

8-PN is the reference point against which other phytoestrogens’ potency is described, and the comparison is the point of the page. In the study that identified it, 8-PN competed with 17β-estradiol for the estrogen receptor with a potency greater than the established phytoestrogens genistein, daidzein and coumestrol ^{1Reference 1Milligan SR et al. · 1999Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beerView study →}. Follow-up endocrine profiling confirmed it binds both ERα and ERβ — with a preference for ERα — and, tellingly, that the structurally related hop flavonoids (isoxanthohumol, 6-prenylnaringenin, xanthohumol) have less than ~1% of 8-PN’s estrogenic activity ^{2Reference 2Milligan SR et al. · 2000The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoidsView study →}. In other words, hops’ estrogenicity is concentrated almost entirely in this one minor molecule.

Two caveats keep the “most potent” claim honest:

• Potent relative to other phytoestrogens, not to estradiol. 8-PN is still orders of magnitude weaker than 17β-estradiol itself — it is the strongest of the plant estrogens, not a match for the human hormone ^{1,18Reference 1Milligan SR et al. · 1999Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beerView study →Reference 18Pohjanvirta R · 2022The potent phytoestrogen 8-prenylnaringenin: a friend or a foe? International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/35328588/View study →}.
• The prenyl group and its position are load-bearing. Moving the prenyl to the 6-position (6-prenylnaringenin) or leaving it off (naringenin) largely abolishes the estrogenicity — the 8-prenyl arrangement is what fits the receptor ^{2Reference 2Milligan SR et al. · 2000The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoidsView study →}.

From Xanthohumol to 8-PN: The Gut-Activation Story

A distinctive pharmacokinetic feature of this molecule is that most dietary 8-PN is not eaten as 8-PN. Hops and beer are much richer in the chalcone xanthohumol and its isomerised flavanone isoxanthohumol than in 8-PN itself. Human gut bacteria O-demethylate isoxanthohumol into 8-PN, and this conversion — carried out in the distal colon, largely by Eubacterium limosum-type organisms — can raise 8-PN exposure up to ~10-fold after intake ^{4,5Reference 4Possemiers S et al. · 2005Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringeninView study →Reference 5Possemiers S et al. · 2006In vitroThe prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestineView study →}.

The catch is enormous interindividual variation: only a subset of people harbour an efficient converting flora (“8-PN producers”). In a dietary intervention trial of fifty post-menopausal women, subjects sorted into poor, moderate and strong producers, with the phenotype tied to microbial and dietary factors rather than to dose ^{6Reference 6Bolca S et al. · 2007Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian womenView study →}. This is why a fixed intake of hops or beer delivers an unpredictable internal 8-PN dose, and why standardised extracts that deliver pre-formed 8-PN are the only way to control exposure.

What It's Used For

The pharmacology is dominated by estrogen-receptor agonism, with anticancer and anti-angiogenic activities that mostly reflect either that estrogenic axis or high-concentration in-vitro effects. The load-bearing discipline: the human efficacy data are for 8-PN-standardised hop extracts at microgram doses, while the anticancer/anti-angiogenic work is preclinical and often at micromolar concentrations far above what those extracts achieve in blood ^{15,16Reference 15Brunelli E et al. · 2007Brunelli E, et al. (2007). 8-Prenylnaringenin inhibits estrogen receptor-alpha mediated cell growth and induces apoptosis in MCF-7 breast cancer cells. The Journal of Steroid Biochemistry and Molecular Biology. https://pubmed.ncbi.nlm.nih.gov/17681752/View study →Reference 16van Breemen RB et al. · 2020Pharmacokinetic interactions of a hop dietary supplement with drug metabolism in perimenopausal and postmenopausal womenView study →}.

Evidence by IndicationStrength of support · Beta

Support is an experimental score — weighted by study type (human > animal > in vitro) and volume. A beta, not a validated metric. Human data are the 8-PN-standardised extract, not the pure isolate, so read the per-row basis.

01Menopausal Symptoms / Hot FlushesShaky44%Small placebo-controlled RCTs of 8-PN-standardised hop extract + ovariectomy hot-flush model ^{8,9,10Reference 8Heyerick A et al. · 2006RCTA first prospective, randomized, double-blind, placebo-controlled study on the use of a standardized hop extract to alleviate menopausal discomfortsView study →Reference 9Erkkola R et al. · 2010RCTA randomized, double-blind, placebo-controlled, cross-over pilot study on the use of a standardized hop extract to alleviate menopausal discomfortsView study →Reference 10Bowe J et al. · 2006AnimalThe hop phytoestrogen, 8-prenylnaringenin, reverses the ovariectomy-induced rise in skin temperature in an animal model of menopausal hot flushesView study →}

02Estrogenic Activity (mechanism)Promising58%Potent ERα/ERβ binding, isolate — best-characterised property ^{1,2Reference 1Milligan SR et al. · 1999Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beerView study →Reference 2Milligan SR et al. · 2000The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoidsView study →}

03Bone / OsteoporosisShaky34%Ovariectomy-rat + osteoblast/osteoclast in vitro; one human RCT in osteopenia ^{11,12,13Reference 11Hoffmann DB et al. · 2016AnimalEffects of 8-prenylnaringenin and whole-body vibration therapy on a rat model of osteopeniaView study →Reference 12Luo D et al. · 2014Effects and mechanisms of 8-prenylnaringenin on osteoblast MC3T3-E1 and osteoclast-like cells RAW264.7View study →Reference 13Lecomte M et al. · 2023RCTEffect of a hop extract standardized in 8-prenylnaringenin on bone health and gut microbiome in postmenopausal women with osteopenia: a one-year randomized, double-blind, placebo-controlled trialView study →}

04Anti-Angiogenic / AnticancerShaky30%In-vitro/in-vivo angiogenesis inhibition + ER-positive breast-cancer apoptosis, micromolar ^{14,15Reference 14Pepper MS et al. · 2004In vitroPepper MS, et al. (2004). 8-prenylnaringenin, a novel phytoestrogen, inhibits angiogenesis in vitro and in vivo. Journal of Cellular Physiology. https://pubmed.ncbi.nlm.nih.gov/14978739/View study →Reference 15Brunelli E et al. · 2007Brunelli E, et al. (2007). 8-Prenylnaringenin inhibits estrogen receptor-alpha mediated cell growth and induces apoptosis in MCF-7 breast cancer cells. The Journal of Steroid Biochemistry and Molecular Biology. https://pubmed.ncbi.nlm.nih.gov/17681752/View study →}

Mechanisms

The estrogen-receptor agonism is the hub: the menopausal, bone and hot-flush effects all flow from it, and so does the central safety caveat. The anti-angiogenic action is a partly ER-independent, high-concentration effect and sits off the microgram-dose menopausal axis.

Pharmacokinetics

The PK is unusual and central to the molecule. In post-menopausal women, single oral doses of synthetic 8-PN (50, 250, 750 mg) were rapidly absorbed (peak ~1–1.5 h), circulated mostly as conjugated metabolites (glucuronides/sulfates) with only small amounts of free aglycone, and were well tolerated across the whole dose range ^{7Reference 7Rad M et al. · 2006Pharmacokinetics and systemic endocrine effects of the phyto-oestrogen 8-prenylnaringenin after single oral doses to postmenopausal womenView study →}. But the dominant real-world route is indirect: much systemic 8-PN is generated in the colon when gut bacteria demethylate isoxanthohumol, a conversion that can boost exposure ~10-fold but only in the subset of people with the right flora ^{4,5,6Reference 4Possemiers S et al. · 2005Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringeninView study →Reference 5Possemiers S et al. · 2006In vitroThe prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestineView study →Reference 6Bolca S et al. · 2007Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian womenView study →}. A human CYP-probe study of a hop dietary supplement found no clinically significant inhibition of CYP1A2, 2C9, 2D6 or 3A4 in peri-/post-menopausal women — a reassuring drug-interaction datapoint that supersedes alarmist in-vitro reads ^{16Reference 16van Breemen RB et al. · 2020Pharmacokinetic interactions of a hop dietary supplement with drug metabolism in perimenopausal and postmenopausal womenView study →}.

Clinical Trials

Human trials exist but are few and small, and all use 8-PN-standardised hop extracts (or, for PK, synthetic 8-PN) rather than the isolate as a stand-alone drug: two small placebo-controlled menopause trials ^{8,9Reference 8Heyerick A et al. · 2006RCTA first prospective, randomized, double-blind, placebo-controlled study on the use of a standardized hop extract to alleviate menopausal discomfortsView study →Reference 9Erkkola R et al. · 2010RCTA randomized, double-blind, placebo-controlled, cross-over pilot study on the use of a standardized hop extract to alleviate menopausal discomfortsView study →}, a single-dose PK/endocrine study ^{7Reference 7Rad M et al. · 2006Pharmacokinetics and systemic endocrine effects of the phyto-oestrogen 8-prenylnaringenin after single oral doses to postmenopausal womenView study →}, and a one-year bone RCT in osteopenia ^{13Reference 13Lecomte M et al. · 2023RCTEffect of a hop extract standardized in 8-prenylnaringenin on bone health and gut microbiome in postmenopausal women with osteopenia: a one-year randomized, double-blind, placebo-controlled trialView study →}.

Last checked: July 2026.

Isolate vs. Plant Studies

This molecule splits cleanly. The receptor pharmacology is pure-isolate — 8-PN’s ranking as the most potent phytoestrogen, its ERα/ERβ binding, its anti-angiogenic and pro-apoptotic effects are all isolated-compound work, a genuine mechanistic strength ^{1,2,14,15Reference 1Milligan SR et al. · 1999Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beerView study →Reference 2Milligan SR et al. · 2000The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoidsView study →Reference 14Pepper MS et al. · 2004In vitroPepper MS, et al. (2004). 8-prenylnaringenin, a novel phytoestrogen, inhibits angiogenesis in vitro and in vivo. Journal of Cellular Physiology. https://pubmed.ncbi.nlm.nih.gov/14978739/View study →Reference 15Brunelli E et al. · 2007Brunelli E, et al. (2007). 8-Prenylnaringenin inhibits estrogen receptor-alpha mediated cell growth and induces apoptosis in MCF-7 breast cancer cells. The Journal of Steroid Biochemistry and Molecular Biology. https://pubmed.ncbi.nlm.nih.gov/17681752/View study →}. The human efficacy, by contrast, is whole-extract: every menopause and bone trial uses a hop extract standardised to a defined 8-PN content (~100–250 µg/day), not the free molecule ^{8,9,13Reference 8Heyerick A et al. · 2006RCTA first prospective, randomized, double-blind, placebo-controlled study on the use of a standardized hop extract to alleviate menopausal discomfortsView study →Reference 9Erkkola R et al. · 2010RCTA randomized, double-blind, placebo-controlled, cross-over pilot study on the use of a standardized hop extract to alleviate menopausal discomfortsView study →Reference 13Lecomte M et al. · 2023RCTEffect of a hop extract standardized in 8-prenylnaringenin on bone health and gut microbiome in postmenopausal women with osteopenia: a one-year randomized, double-blind, placebo-controlled trialView study →}. Between these sits the gut: because whole hops and beer deliver 8-PN largely via microbial conversion of isoxanthohumol, the internal dose from a plant preparation is neither the label amount nor predictable person-to-person ^{4,5,6Reference 4Possemiers S et al. · 2005Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringeninView study →Reference 5Possemiers S et al. · 2006In vitroThe prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestineView study →Reference 6Bolca S et al. · 2007Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian womenView study →}. The practical upshot — carry the standardised-extract dose tier onto any hops-for-menopause claim, and treat ordinary tea/tincture/beer as an unknown 8-PN dose.

Its Role in Plants

In the hop plant, 8-PN is a minor product of the prenylflavonoid pathway in the lupulin glands, downstream of the abundant chalcone xanthohumol: xanthohumol cyclises to the flavanone isoxanthohumol, and demethylation/prenylation chemistry yields the prenylnaringenins, of which the 8-prenyl isomer is the estrogenic one ^{3Reference 3Stevens JF · 2004Xanthohumol and related prenylflavonoids from hops and beer: to your good health! Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/15231405/View study →}. The prenylated flavonoids and the co-located bitter acids of the lupulin gland are part of the plant’s chemical defence and, for hops as a cultivated crop, its resin/aroma value — the estrogenic activity that matters to humans is essentially a side-effect of this defensive/secondary chemistry, not a function the plant evolved for us ^{3Reference 3Stevens JF · 2004Xanthohumol and related prenylflavonoids from hops and beer: to your good health! Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/15231405/View study →}.

Prevalence in Nature

8-PN is, for practical purposes, a hops-specific molecule: it occurs in the cones (strobiles) of Humulus lupulus and, by extension, in beer and in hop-based supplements. Even within hops it is a minor constituent — usually well under 0.1% of the dried cone and far less abundant than xanthohumol or isoxanthohumol — and its level varies widely with cultivar, growing conditions and storage, degrading over time ^{3Reference 3Stevens JF · 2004Xanthohumol and related prenylflavonoids from hops and beer: to your good health! Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/15231405/View study →}. In beer it is present only at trace µg/L concentrations, which is why dietary exposure hinges so heavily on gut conversion of the more plentiful isoxanthohumol rather than on pre-formed 8-PN ^{4,5Reference 4Possemiers S et al. · 2005Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringeninView study →Reference 5Possemiers S et al. · 2006In vitroThe prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestineView study →}. Because the reported figures are heterogeneous and method-dependent, a quantitative content-by-source chart is deferred to the gaps tracker rather than shown with unreliable numbers.

Discovery & Synthesis

8-PN’s estrogenic identity was pinned down in 1999, when Milligan, De Keukeleire, Stevens and colleagues identified it as the potent phytoestrogen of hops and beer — the molecular explanation for the long-noted estrogenic effects of hops on female hop-pickers ^{1Reference 1Milligan SR et al. · 1999Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beerView study →}. The following year the same group profiled its ERα/ERβ binding and showed the related hop flavonoids were essentially inactive by comparison ^{2Reference 2Milligan SR et al. · 2000The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoidsView study →}. The trivial name hopein reflects the hop origin.

Because 8-PN occurs at low natural abundance, research and supplement material is generally obtained by semi-synthesis from the plentiful hop chalcone xanthohumol rather than by extraction of 8-PN itself: controlled demethylation of xanthohumol yields 8-PN (with 6-prenylnaringenin as a regioisomeric by-product), and modern work has optimised a microwave-assisted, design-of-experiments demethylation to improve the 8-PN:6-PN ratio and yield ^{19Reference 19Urmann C et al. · 2020Semi-synthetic approach leading to 8-prenylnaringenin and 6-prenylnaringenin: optimization of the microwave-assisted demethylation of xanthohumol using design of experimentsView study →}. The pharmacokinetic study of pure 8-PN likewise used chemically synthesised material ^{7Reference 7Rad M et al. · 2006Pharmacokinetics and systemic endocrine effects of the phyto-oestrogen 8-prenylnaringenin after single oral doses to postmenopausal womenView study →}. Manufacture today therefore leans on xanthohumol-derived semi-synthesis and on hop extracts standardised to a defined 8-PN content.

Patents: not yet researched.

Toxicity & Safety

8-PN carries a low toxicity flag at dietary and supplement exposures — hops and beer have a long consumption history, single oral doses up to 750 mg were well tolerated in a controlled study ^{7Reference 7Rad M et al. · 2006Pharmacokinetics and systemic endocrine effects of the phyto-oestrogen 8-prenylnaringenin after single oral doses to postmenopausal womenView study →}, and a human probe study found no meaningful CYP-mediated drug-interaction signal ^{16Reference 16van Breemen RB et al. · 2020Pharmacokinetic interactions of a hop dietary supplement with drug metabolism in perimenopausal and postmenopausal womenView study →}. The real caution is not toxicological but hormonal: this is the most potent phytoestrogen known, so concentrated hop/8-PN products behave like a weak estrogen and should be treated with the caution that implies.

Safety at a Glance

✅ Low / no toxicity

• Low intrinsic toxicity at usual exposures. Long dietary history via hops/beer; single oral doses to 750 mg tolerated; no clinically significant CYP1A2/2C9/2D6/3A4 interaction in a human hop-supplement probe study ^{7,16Reference 7Rad M et al. · 2006Pharmacokinetics and systemic endocrine effects of the phyto-oestrogen 8-prenylnaringenin after single oral doses to postmenopausal womenView study →Reference 16van Breemen RB et al. · 2020Pharmacokinetic interactions of a hop dietary supplement with drug metabolism in perimenopausal and postmenopausal womenView study →}.
• Most potent phytoestrogen known — avoid in hormone-sensitive conditions. Concentrated hop/8-PN supplements act as an estrogen agonist; caution in oestrogen-receptor-positive breast cancer, endometriosis and other hormone-sensitive disease, and with hormone therapy or endocrine treatments, without medical advice ^{1,2,18Reference 1Milligan SR et al. · 1999Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beerView study →Reference 2Milligan SR et al. · 2000The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoidsView study →Reference 18Pohjanvirta R · 2022The potent phytoestrogen 8-prenylnaringenin: a friend or a foe? International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/35328588/View study →}.
• Unpredictable real dose from plants. Because gut bacteria generate much 8-PN from isoxanthohumol, the internal dose from hops, beer or tinctures varies widely between people and is not the label amount ^{4,5,6Reference 4Possemiers S et al. · 2005Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringeninView study →Reference 5Possemiers S et al. · 2006In vitroThe prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestineView study →Reference 6Bolca S et al. · 2007Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian womenView study →}.
• Reproductive/endocrine signalling is inherent. As a strong estrogen-receptor agonist, 8-PN engages the same axis as endogenous estrogen; estrogenic and reproductive findings for the isolate are reported here as cautions, with intake decisions belonging to the herb/product page.

Dosage

There is no established dose for isolated 8-PN, and it is not marketed as a stand-alone drug. The figures that exist are research figures at two very different scales:

The gulf between the microgram doses that produced the menopausal/bone signals and the milligram doses used only to characterise pharmacokinetics is itself a caution against extrapolating from high-dose experiments. Ordinary hop tea, tincture or beer delivers an unknown and person-dependent amount because much 8-PN is made by gut bacteria from isoxanthohumol ^{4,5,6Reference 4Possemiers S et al. · 2005Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringeninView study →Reference 5Possemiers S et al. · 2006In vitroThe prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestineView study →Reference 6Bolca S et al. · 2007Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian womenView study →}. These are doses studied in research and are not a personal recommendation.

References

1. Milligan SR, et al. (1999). Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beer. The Journal of Clinical Endocrinology & Metabolism. https://pubmed.ncbi.nlm.nih.gov/10372741/
2. Milligan SR, et al. (2000). The endocrine activities of 8-prenylnaringenin and related hop (Humulus lupulus L.) flavonoids. The Journal of Clinical Endocrinology & Metabolism. https://pubmed.ncbi.nlm.nih.gov/11134162/
3. Stevens JF, Page JE (2004). Xanthohumol and related prenylflavonoids from hops and beer: to your good health! Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/15231405/
4. Possemiers S, et al. (2005). Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringenin. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/16076107/
5. Possemiers S, et al. (2006). The prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestine. The Journal of Nutrition. https://pubmed.ncbi.nlm.nih.gov/16772450/
6. Bolca S, et al. (2007). Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian women. The British Journal of Nutrition. https://pubmed.ncbi.nlm.nih.gov/17521469/
7. Rad M, et al. (2006). Pharmacokinetics and systemic endocrine effects of the phyto-oestrogen 8-prenylnaringenin after single oral doses to postmenopausal women. British Journal of Clinical Pharmacology. https://pubmed.ncbi.nlm.nih.gov/16934044/
8. Heyerick A, et al. (2006). A first prospective, randomized, double-blind, placebo-controlled study on the use of a standardized hop extract to alleviate menopausal discomforts. Maturitas. https://pubmed.ncbi.nlm.nih.gov/16321485/
9. Erkkola R, et al. (2010). A randomized, double-blind, placebo-controlled, cross-over pilot study on the use of a standardized hop extract to alleviate menopausal discomforts. Phytomedicine. https://pubmed.ncbi.nlm.nih.gov/20167461/
10. Bowe J, et al. (2006). The hop phytoestrogen, 8-prenylnaringenin, reverses the ovariectomy-induced rise in skin temperature in an animal model of menopausal hot flushes. The Journal of Endocrinology. https://pubmed.ncbi.nlm.nih.gov/17088409/
11. Hoffmann DB, et al. (2016). Effects of 8-prenylnaringenin and whole-body vibration therapy on a rat model of osteopenia. Journal of Nutrition and Metabolism. https://pubmed.ncbi.nlm.nih.gov/26904278/
12. Luo D, et al. (2014). Effects and mechanisms of 8-prenylnaringenin on osteoblast MC3T3-E1 and osteoclast-like cells RAW264.7. Food Science & Nutrition. https://pubmed.ncbi.nlm.nih.gov/25473491/
13. Lecomte M, et al. (2023). Effect of a hop extract standardized in 8-prenylnaringenin on bone health and gut microbiome in postmenopausal women with osteopenia: a one-year randomized, double-blind, placebo-controlled trial. Nutrients. https://pubmed.ncbi.nlm.nih.gov/37375599/
14. Pepper MS, et al. (2004). 8-prenylnaringenin, a novel phytoestrogen, inhibits angiogenesis in vitro and in vivo. Journal of Cellular Physiology. https://pubmed.ncbi.nlm.nih.gov/14978739/
15. Brunelli E, et al. (2007). 8-Prenylnaringenin inhibits estrogen receptor-alpha mediated cell growth and induces apoptosis in MCF-7 breast cancer cells. The Journal of Steroid Biochemistry and Molecular Biology. https://pubmed.ncbi.nlm.nih.gov/17681752/
16. van Breemen RB, et al. (2020). Pharmacokinetic interactions of a hop dietary supplement with drug metabolism in perimenopausal and postmenopausal women. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/32285669/
17. Štulíková K, et al. (2018). Therapeutic perspectives of 8-prenylnaringenin, a potent phytoestrogen from hops. Molecules. https://pubmed.ncbi.nlm.nih.gov/29543713/
18. Pohjanvirta R, Nasri A (2022). The potent phytoestrogen 8-prenylnaringenin: a friend or a foe? International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/35328588/
19. Urmann C, et al. (2020). Semi-synthetic approach leading to 8-prenylnaringenin and 6-prenylnaringenin: optimization of the microwave-assisted demethylation of xanthohumol using design of experiments. Molecules. https://pubmed.ncbi.nlm.nih.gov/32887388/

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