Inositol for Hair: What the Research Shows

Inositol is sometimes called a B-vitamin-like compound, and it is promoted for hair. We found no human trial of inositol on hair loss. The research is a rat study of a complex containing inositol, and two small studies in women with polycystic ovary syndrome (PCOS), where hair and skin outcomes were acne and excess hair.

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Key Takeaways

• We found no human trial of inositol for hair loss.
• In rats, an inositol-stabilized arginine silicate complex, alone or with biotin, increased hair density and the proportion of follicles in growth, compared with controls.
• In 50 women with PCOS, myo-inositol for 6 months was followed by lower testosterone and reduced hirsutism and acne.
• In 200 women with PCOS, a supplement with myo-inositol, magnesium and folic acid was followed by lower testosterone and improved acne and hirsutism, in a retrospective study.

What Is Inositol?

Inositol is a sugar-like compound. Myo-inositol, an isoform, has been described as belonging to the vitamin B complex.

Does Inositol Help Hair?

Not shown for hair loss. The animal result is for a combination product, and the human studies are in women with PCOS and don't measure scalp hair.

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Using Inositol Sensibly

• If you suspect PCOS, see a doctor. It is a medical condition with its own care.
• Don't expect hair regrowth from inositol on its own.
• Ask your doctor before taking supplements, especially with medicines.

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What The Research Shows

Rat Study Of A Combination

Twenty-eight female rats were shaved and given an inositol-stabilized arginine silicate complex (ASI), with or without magnesium biotinate. On day 42, hair density and the anagen ratio increased and the telogen ratio decreased in all supplemented groups compared with control, with changes in several growth-factor markers. The authors concluded the combination could promote hair growth in this model (Demir et al., 2023). It was a rodent study of a complex, not inositol alone.

PCOS And Skin

Fifty women with PCOS took myo-inositol for 6 months. After 3 months, plasma LH, testosterone, free testosterone, insulin and HOMA index were significantly reduced, and both hirsutism and acne decreased after 6 months. The authors described it as a simple and safe therapy for the metabolic profile (Zacchè et al., 2009). Hirsutism is excess hair, not hair loss.

A Retrospective Study

A retrospective study of 200 women with PCOS followed a supplement containing myo-inositol, microlipodispersed magnesium and folic acid for 6 months. It showed significant reductions in BMI, testosterone, free testosterone and DHEAS, and improvement in acne and hirsutism (Pezza et al., 2025). It had no control group.

Magnesium is another supplement people pair with it; see magnesium and hair.

See also: L-Arginine for Hair: What the Research Shows · Pantothenic Acid (Vitamin B5) for Hair: What the Research Shows

Frequently Asked Questions

Does inositol help hair loss?

We found no human trial showing that.

Does inositol help PCOS?

The small studies above reported lower testosterone and less acne and excess hair. A doctor should guide PCOS care.

Is inositol safe?

One study called it safe in PCOS patients; check with your doctor.

References

1. Demir B, Cicek D, Orhan C, et al. Effects of a Combination of Arginine Silicate Inositol Complex and a Novel Form of Biotin on Hair and Nail Growth in a Rodent Model. Biol Trace Elem Res. 2023. PubMed
2. Zacchè MM, Caputo L, Filippis S, et al. Efficacy of myo-inositol in the treatment of cutaneous disorders in young women with polycystic ovary syndrome. Gynecol Endocrinol. 2009. PubMed
3. Pezza M, Carlomagno V, Sammarco E, et al. Association of Myo-Inositol and Microlipodispersed Magnesium in Androgen-Dependent Dermatological Diseases: A Retrospective Study. Pharmaceuticals (Basel). 2025. PubMed