One of the most common medications in the world, metformin and is best known as a treatment for type 2 diabetes and insulin resistance in PCOS. But beyond its traditional uses, there’s growing evidence that it may also stimulate hair growth. It seems that this humble anti-diabetic drug can potentially be useful in some cases of hair loss. In this article, we’ll explore the science behind using or and topical metformin for hair loss treatment. We’ll review how metformin works to grow thicker hair as well as risk and limitations.
What is Metformin?
Metformin is a prescription only medicine that is commonly used to lower blood glucose levels. It improves the body’s sensitivity to insulin and reduces liver glucose production. In addition to its main use in type 2 diabetes, metformin is frequently prescribed off-label for polycystic ovary syndrome (PCOS) and pre-diabetes. The benefits of metformin don;t stop there though! In fact, it may be a bit of a wonder drug with research showing it may have benefits for weight loss, cancer, anti-ageing and brain health. More recently, there’s been growing interest on metformin’s impact on the skin and hair follicle health. It is likley to work through anti-inflammatory, hormonal and cellular mechanisms.
How Does Metformin Make Hair Grow?
Whilst it’s certainly not a standard hair loss treatment, there is evidence that metformin has the potential to support thicker hair growth. Studies show that both oral and topical metformin may treat hair loss due to inflammatory causes like scarring alopecia. Although research is ongoing, metformin’s effect on hair growth is likely due to the following mechanisms:
- Hormonal Modulation: One of the main actions of metformin is its ability to improve insulin sensitivity thus reducing circulating insulin levels which can lower androgen levels. It may be important in conditions like PCOS or androgenetic alopecia where excess androgens can shrink hair follicles and disrupt the growth cycle.
- Anti-inflammatory Properties: Chronic scalp inflammation plays a major role in several types of hair loss, especially scarring forms like central centrifugal cicatricial alopecia (CCCA). Metformin has anti-inflammatory effects that may help to calm this environment and support the recovery of affected follicles.
- Cellular Regeneration: Studies suggest metformin may affect the pathways that control hair follicle cycling to encourage dormant follicles to re-enter the growth (anagen) phase. This raises the exciting possibility that metformin might actually support hair growth.
Which Types of Hair Loss Can Metformin Help Treat?
Doctors may use metformin off-license for some patients who have not responded to conventional treatments especially if there is a risk of permanent hair follicle damage. Below are the types of hair loss it may help treat:
- Scarring Alopecia: This is what the majority of research has been on. Oral and topical metformin may help grow hair and stop loss in scarring alopecias like CCCA. These conditions are often unresponsive to conventional treatments. They can cause cause permanent irreversible hair follicle damage and baldness.
- Androgenetic Alopecia: There is very early evidence that metformin could potentially support hair regrowth in male and female pattern hair loss.
- PCOS-Related Hair Loss: In women with polycystic ovary syndrome, excess androgens can lead to hair thinning at the crown and temples causing male pattern hair loss. Metformin may help reduce loss and grow thicker hair by addressing the underlying metabolic and hormonal imbalance.
Risks & Side Effects
Metformin has been in use for diabetes since the 1950s and has a good safety profile. Systemic side effects are also less likely in topical form. However, as with any medications there are still some possible risks:
- Vitamin B12 Deficiency: Long-term oral use can reduce vitamin B12 absorption. This can potentially lead to fatigue, hair thinning and other symptoms.
- Gastrointestinal Upset: This is common with oral forms especially when starting treatment. Nausea, bloating and diarrhoea usually subside with time or dose adjustment.
- Rare but Serious Reactions: Lactic acidosis is a rare but serious side effect of oral metformin. This is extremely unlikely with topical use but we still can’t completely rule it out.
- Topical Side Effects: When used on the scalp, metformin cream may cause mild irritation or dryness in some people.
Other Hair Loss Treatments
Although there’s a fair bit of excitement around metformin’s potential to support hair regrowth, it’s unlikely to be a silver bullet or “miracle treatment”. Like most hair loss treatments, its true power lies in using it for the right patients and likely in combination with other treatments. The below are common non invasive hair loss treatments that may be an alternative or useful alongside metformin:
- Minoxidil: Still the cornerstone of hair regrowth treatments, minoxidil is available in topical and oral form. It works by increasing blood flow to the scalp and stimulating follicles to prolong the active growth.
- Dihydrotestosterone (DHT) Blockers: DHT is a key driver in androgenetic hair loss. Finasteride and Dutasteride help block the conversion of testosterone to DHT thus slowing hair loss and potentially reversing it. These can be used orally or increasingly topically to try to reduce risk of systemic side effects.
- Spironolactone: This anti-androgen drug that reduces the effects of testosterone and DHT on the hair follicle. It may be used in both oral and topical form to treat hormone related hair loss.
- Anti-inflammatories: For those with scarring types of alopecia (e.g. CCCA or lichen planopilaris), reducing inflammation is essential to protect the hair follicles. Steroids like hydrocortisone or clobetasone, calcineurin inhibitors and antibiotics can help reduce inflammation.
- Melatonin and Caffeine-Based Products: Melatonin is a powerful antioxidant that has been shown to extend the hair growth phase. It is often used topically alongside other hair loss treatments. Caffeine can also help stimulate hair follicles. It is available as a standalone treatment for early loss in shampoos or serums. You can also find caffeine with other ingredients in compounded prescription treatments.
- Nutritional Support: No hair treatment plan is complete without addressing nutrition. Vitamin B12 deficiency is a known risk with long-term oral metformin use and can contribute to hair thinning. Similarly, low iron or ferritin levels can impair hair growth. Regular blood work and targeted supplementation (especially for B12, iron, vitamin D, and zinc) may help support healthy hair regrowth.
Although far from a miracle cure, metformin may be a valuable tool to stop loss and help grow thicker hair in people with scarring alopecias or hormonal imbalances. Its benefits for hair are likely due to its effects on metabolism, inflammation and follicular regeneration. However, studies are still far and few between so more higher level research is necessary to fully reveal its potential.
We are passionate about personalised beauty which is why we offer custom topical hair loss and regrowth treatments through our online clinic. Our doctors create custom hair growth treatments using ingredients like Minoxidil, Finasteride, Dutasteride, Spironolactone, Melatonin, Caffeine and Tretinoin where appropriate for each and every patient. Start your virtual consultation and begin your journey to great hair today.
