Resveratrol and Pterostilbene: Effects on Hormones and PCOS

Resveratrol in PCOS: promising but contradictory

This is where it gets interesting, and honest. There are individual, often-cited studies with positive results. In a double-blind study by Banaszewska and colleagues, resveratrol significantly lowered androgen levels over three months, in conjunction with improved insulin sensitivity. A 2023 meta-analysis across four small studies also found reductions in testosterone, LH, and DHEAS.

But that's only half the story. Another meta-analysis, published in the journal Endocrine in 2024, found no significant effect on testosterone, FSH, LH, BMI, or hirsutism. The only positive outcomes here were prolactin, acne score, and cholesterol. In other words, depending on which studies are summarized, the results vary.

Why these contradictions? The studies are small, use different dosages, and are short, and resveratrol is quickly broken down in the body. The honest assessment is therefore: resveratrol is a promising candidate for PCOS, but a clear, reliable effect has not yet been proven.

Pterostilbene: better absorption, thinner data

Pterostilbene is considered the more interesting of the two substances due to its better bioavailability. In research, it is associated with anti-inflammatory effects, a modulation of cytokines such as IL-6 and TNF-alpha, and a possible improvement in insulin sensitivity.

The source of these findings is important here. Data on insulin sensitivity and the gut microbiome primarily come from animal studies, for example, investigations in rats where pterostilbene reduced fat mass and favorably altered the microbiome. In humans, pterostilbene has been well tolerated in a safety study at up to 250 mg daily, but specific efficacy studies in PCOS are still lacking.

Pterostilbene is therefore a highly interesting substance with a good theoretical basis, but its benefits in humans have not yet been confirmed in larger clinical trials.

What the two substances could affect

When summarizing the research, several areas emerge in which resveratrol and pterostilbene are being investigated. It is important to note that these are discussed correlations, not confirmed promises of efficacy:

• Hormone regulation: In individual studies, markers such as testosterone, LH, and DHEAS decreased under resveratrol. Other studies found no effect.
• Insulin sensitivity: Both substances are associated with a more favorable glucose metabolism, with pterostilbene primarily in preclinical studies.
• Inflammation and oxidative stress: a consistent theme in laboratory research, but less clear clinically.
• Gut microbiome: Pterostilbene favorably altered the bacterial composition in animal studies; human data is lacking.

What foods contain them?

Resveratrol is found primarily in red grape skins and to a lesser extent in red wine. Pterostilbene is found primarily in blueberries. However, the amounts in normal portions are small, well below the doses used in studies. A polyphenol-rich diet with berries, grapes, and colorful vegetables is still useful because it provides many different protective plant compounds, not just these two.

Who is this relevant for?

If you have PCOS, resveratrol and pterostilbene are among the substances being researched as supplementary building blocks, alongside better-established approaches such as myo-inositol, diet, and exercise. They are not a substitute for medical treatment and not a guarantee of changes. Anyone wishing to try them should do so as part of an overall concept and with realistic expectations.

The most important points at a glance

• Resveratrol is well-researched, but the results for PCOS are contradictory, and a reliable effect has not been proven.
• Pterostilbene is better absorbed, but the efficacy data primarily comes from animal and laboratory studies.
• Both are associated with hormones, insulin, and inflammation, much of which is preclinical.
• Through diet alone therapeutic doses are hardly achievable.
• Conceivable as a supplement, but no substitute for proven measures and medical supervision.

Conclusion

Resveratrol and pterostilbene are fascinating plant compounds with a good theoretical basis for hormonal and metabolic health. However, to be honest: the clinical evidence for resveratrol in PCOS is mixed, and for pterostilbene, it still relies heavily on animal studies. Both are interesting supplements, not miracle cures.

They are most effective when integrated into an overall concept of a polyphenol-rich diet, well-proven active ingredients, and a healthy lifestyle. If you are unsure what makes sense for you, a medical consultation is worthwhile.