Hair Growth Vitamins and Supplements: What Actually Works in the UK

Hair growth vitamins and supplements in the UK have become a multi-million pound industry, with countless products making bold claims about transforming hair thickness and stopping hair loss. For anyone navigating this market, the challenge is identifying which supplements are supported by genuine evidence and which represent little more than expensive marketing. This guide provides an honest, evidence-based assessment of the most commonly used hair growth supplements.

Biotin for hair growth: the most overhyped supplement?

Biotin (vitamin B7) is the most heavily marketed hair growth supplement worldwide, yet the evidence for its efficacy in people without a deficiency is notably thin. Biotin deficiency does cause hair loss — but true deficiency is rare in people who eat a reasonably varied diet. The overwhelming majority of individuals taking biotin supplements for hair growth are not deficient and are unlikely to see meaningful benefit. If you want to test whether biotin is relevant for you, a simple blood test can assess your levels before spending money on supplementation.

Iron and ferritin: the most commonly missed cause

Low ferritin — the body’s iron storage protein — is one of the most frequently identified nutritional causes of hair loss in women, and is often present even without full anaemia. Studies suggest ferritin levels need to be above 70 µg/L for optimal hair growth — a level many women, particularly those with heavy periods, fall well below. If you have not had your ferritin tested and are experiencing hair loss, this is the single most important test to request from your GP.

Vitamin D hair growth evidence

Vitamin D receptors are present in hair follicle cells, and vitamin D deficiency has been associated with several forms of hair loss including alopecia areata and telogen effluvium. Given that vitamin D deficiency is extremely common in the UK — the NHS recommends supplementation for all adults from October to March — this is one supplement with a genuinely strong rationale for broad use. A daily supplement of 10 µg (400 IU) is the NHS recommendation, though many specialists suggest higher doses for those found to be deficient.

Zinc, omega-3s, and collagen

Zinc deficiency is associated with hair loss and is underdiagnosed. Omega-3 fatty acids support scalp health and reduce inflammation, and have shown some promise in small studies for hair density. Collagen supplements, while popular, have less direct evidence for hair growth specifically — though adequate dietary protein overall is undeniably important.

Topical treatment alongside supplements

Supplements address internal nutritional factors but do not directly nourish the scalp environment. Combining targeted supplementation with a regular topical treatment gives the most comprehensive approach. ZenGold Hair Growth Oil delivers natural botanical actives directly to the scalp, working alongside your nutritional strategy. For skin health alongside hair supplementation, explore Scarnil Scar Remover.

Related guide: For a comprehensive overview, read our complete guide: The Best Hair Growth Oil for Women in the UK: A Complete Guide