Biotin supplements are one of the most popular over-the-counter remedies for hair loss, with the global biotin market valued at over £400 million. But does swallowing a biotin pill actually make your hair grow? The answer is more nuanced than supplement companies would have you believe.
What Is Biotin?
Biotin (Vitamin B7, also called Vitamin H) is a water-soluble B vitamin that acts as a cofactor for five carboxylase enzymes in the body. These enzymes are involved in:
- Fatty acid synthesis — critical for cell membrane integrity
- Amino acid metabolism — essential for protein production, including keratin
- Gluconeogenesis — energy production for rapidly dividing cells like hair follicles
Keratin — the structural protein that makes up 95% of the hair shaft — depends on these metabolic pathways. So in theory, biotin is essential for healthy hair.
The Evidence: What Studies Actually Show
When Biotin Works
A 2017 systematic review in Skin Appendage Disorders examined all published studies on biotin and hair loss. The finding: biotin supplementation improved hair growth in 100% of cases where patients had a documented biotin deficiency.
Biotin deficiency causes unmistakable symptoms: brittle nails, skin rashes, and progressive hair thinning. In these cases, supplementation produces clear, rapid improvement.
When Biotin Doesn't Work
Here's the catch: biotin deficiency is actually quite rare in the general population. Most people get adequate biotin from their diet (eggs, nuts, seeds, salmon, sweet potatoes). If you're not deficient, taking extra biotin is unlikely to produce noticeable hair growth on its own.
The studies showing dramatic results were almost exclusively in deficient individuals. For people with normal biotin levels, oral supplements may not move the needle significantly.
Topical vs Oral Biotin
This is where it gets interesting. While oral biotin supplements face absorption limitations and only help if you're deficient, topical biotin applied directly to the scalp may work differently.
When biotin is applied topically in a penetrating formulation, it can reach the dermal papilla cells at the base of the follicle — exactly where keratin synthesis occurs. This bypasses the dietary absorption question entirely.
This is why our Hair Growth Serum includes biotin as part of its multi-active complex, delivered directly to the scalp alongside 5% minoxidil, rather than relying on oral supplementation alone.
Who Should Consider Biotin Supplementation?
You may benefit from biotin supplements if you:
- Are pregnant or breastfeeding (biotin requirements increase)
- Take certain medications (anticonvulsants, antibiotics)
- Have a gastrointestinal condition affecting nutrient absorption
- Follow a very restrictive diet
- Notice brittle nails alongside hair thinning (classic deficiency sign)
The Smart Approach
Rather than relying on biotin alone, the most effective strategy combines multiple approaches:
- Topical treatment — A clinically proven serum with 5% minoxidil + topical biotin delivered directly to the scalp
- Nutrition — Ensure adequate dietary biotin through whole foods (eggs, nuts, avocado)
- Address the real cause — If you're experiencing pattern hair loss, minoxidil targets the underlying follicle miniaturisation that biotin alone cannot address
The Bottom Line
Biotin is a genuine building block for healthy hair — but it's not a magic bullet. If you're deficient, supplementation will help dramatically. If you're not, a topical formulation that delivers biotin directly to the follicle alongside clinically proven actives like minoxidil is a far more effective strategy than pills alone.