From the Guidelines
Biotin supplements are typically recommended at doses of 2.5-10 mg (2,500-10,000 mcg) daily for those seeking to improve hair growth, though evidence for its effectiveness is limited. The most common dose used in studies is 5 mg (5,000 mcg) daily 1. Biotin works best for people who have an underlying deficiency, which is rare but can occur in pregnant women, people with certain genetic disorders, alcoholics, or those taking specific medications like anticonvulsants. As a B vitamin (B7), biotin supports keratin production, the protein that makes up hair, skin, and nails. Results, if any, typically take 3-6 months of consistent use to become noticeable.
Key Considerations
- Biotin is water-soluble and generally considered safe even at higher doses, with excess simply excreted in urine 1.
- However, biotin supplements can interfere with certain laboratory tests, particularly thyroid function and cardiac marker tests, so inform your healthcare provider if you're taking biotin before undergoing blood tests.
- For most people with normal diets, focusing on overall nutrition may be more beneficial for hair health than biotin supplementation alone.
- Recent guidelines suggest that biotin needs in pregnancy might be higher than the current recommendations, with some studies indicating benefits from higher doses 1.
Dosage and Safety
- The recommended dose for biotin supplementation can vary, but 5 mg (5,000 mcg) daily is a common and relatively safe dose 1.
- Higher doses, up to 10 mg/day, may be necessary in cases of malabsorption or deficiency 1.
- It's essential to consult with a healthcare provider before starting biotin supplements, especially if you're pregnant, have a genetic disorder, or are taking certain medications.
From the Research
Biotin for Hair Growth
- Biotin is a water-soluble B vitamin that acts as an essential cofactor for several carboxylases involved in the cellular metabolism of fatty acids, amino acids, and gluconeogenesis 2.
- There is limited research to support the utility of biotin in healthy individuals for hair growth, and its efficacy for hair remains largely unsubstantiated in scientific literature 2, 3.
- Biotin deficiency was found in 38% of women complaining of hair loss, and the custom of treating women complaining of hair loss with oral biotin supplementation is to be rejected, unless biotin deficiency and its significance for the complaint of hair loss in an individual has been demonstrated 4.
Recommended Dose and Effectiveness
- The use of 10 mg/day biotin can prevent the mucocutaneous adverse effects of isotretinoin treatment and decrease telogen and increase anagen hair rates 5.
- Biotin administration may improve the treatment of hair loss when deficiency is detected on the basis of a careful patient history, clinical examination, and the determination of serum biotin levels 6.
- Correct doses used in dermatological conditions are safe and are not at risk of interference with laboratory tests, but administration should be controlled by physicians and follow a medical diagnosis and prescription 6.
Key Findings
- There have been no clinical trials conducted to investigate the efficacy of biotin supplementation for the treatment of alopecia of any kind, nor has there been any randomized controlled trial to study its effect on hair quality and quantity in human subjects 2.
- Biotin supplementation may be of benefit in cases of acquired and inherited causes of biotin deficiency, as well as pathologies such as brittle nail syndrome or uncombable hair 3.
- The tolerability of biotin is excellent, and there is no risk of hypervitaminosis even in the case of high doses 6.