Hair growth supplements intended to treat hair loss (hair loss) typically contain one or a combination of seven vitamins, minerals, and macronutrients that are essential for hair growth. These are protein, collagen, omega-3 fatty acids, zinc, biotin, iron and selenium.
Although some success has been shown (especially when nutritional deficiencies are the cause of hair loss), the safety and effectiveness of hair growth supplements remains unclear.
In the United States, the Food and Drug Administration (FDA) does not regulate supplements in the same way as prescription drugs. This means that some supplement products may not contain what is listed on the label. When choosing a supplement, look for third-party tested products and consult your health care provider, registered dietitian, nutritionist (RD or RDN), or pharmacist.
Nutrients important for hair growth
The hair follicle cycle mainly consists of micronutrients (vitamins and minerals).
Hair loss caused by nutrient deficiencies can be reversed by supplementing with vitamins and minerals.
Here’s a look at the evidence behind some popular supplements used for hair loss.
protein
Hair is primarily made of proteins such as keratin, so increasing your protein intake could theoretically boost growth. But there isn’t much evidence yet.
The body typically requires at least 0.8 grams (g) of protein for every kilogram (kg) of body weight (g/kg) to function properly. However, the following groups of people require more protein per day.
toddler athlete
People who are malnourished, people who are fighting infections, people who have undergone surgery.
Keratin is not absorbed into the body, so ingesting it directly has no effect on hair loss. Some products on the market for hair growth contain amino acids such as cysteine, which is produced by the body into keratin. Further research is needed before these can be recommended.
Small trials have shown that fish protein products are effective in reducing hair loss and increasing hair thickness in women with thinning hair.
A woman brushes her curly hair with a comb in the bathroom mirror.
Taras Grebinets/Getty Images
collagen
Collagen is a popular supplement for hair, skin, and nails. However, there isn’t much evidence that it lives up to the hype.
In a small study of 44 healthy women, taking 2.5 ga of collagen peptides per day increased hair follicle and hair thickness.
A combination product containing collagen, peptides, lipids and hyaluronic acid left hair softer and shinier after 8 weeks. However, since multiple ingredients are used, it is unclear how effective collagen alone is.
omega 3 fatty acids
Eyebrow loss and lightening of hair are associated with decreased levels of omega-3 fatty acids.
Products containing omega-3 fatty acids, as well as other fatty acids and antioxidants, reported improved hair thickness and reduced hair loss in women who took the supplement. Again, since this is a combination product, it is impossible to know how much of the effect was caused by the omega-3 fatty acids alone.
zinc
Low zinc levels can cause a certain form of hair loss called telogen effluvium, which is usually reversible. However, there is not enough data to know whether zinc supplementation prevents or reverses hair loss or what the optimal dose is.
A dose of 50 milligrams (mg) per day has been studied in women with hair loss. In this trial, about half of the women who took zinc reported improvement in hair loss.
The recommended daily amount of zinc for adults is as follows:
11 mg for men, 8 mg for women, 11 mg during pregnancy, 12 mg during breastfeeding
Foods high in zinc include:
Too much zinc can cause side effects such as vomiting and diarrhea. Additionally, taking large amounts of zinc over a long period of time (usually several weeks) can have the following consequences:
Copper deficiency anemia decreased immune function
biotin
Many people use biotin (vitamin B7) to prevent or treat hair loss. Although it is actively marketed for this purpose, there is little evidence that it is effective unless you have a biotin deficiency.
In fact, evidence for the use of biotin for hair growth is limited to case studies of children with a rare condition called familial hair-uncombing syndrome. Those who used 5 mg of biotin per day.
Adults over 19 years of age need 30 micrograms (mcg) of biotin daily, and 35 micrograms (mcg) of biotin while breastfeeding. Protein-rich foods such as meat and eggs are good sources of biotin.
Biotin deficiency is very rare in people who eat a balanced diet. In addition to hair loss, other symptoms of low biotin levels include rashes and brittle nails.
Keep in mind that biotin supplements can also cause false test results in heart and thyroid disease tests. Consult your health care provider before taking biotin.
iron
Iron is essential for rapidly dividing cells such as hair follicles. Decreased iron levels are associated with hair loss.
According to the Food and Nutrition Board (FNB) of the National Academies Institute of Medicine (IOM), adults need the following amounts of iron each day:
Men 8 mg Women ages 19-50 18 mg Women over 8 mg Pregnancy 5127 mg Breastfeeding 9 mg
If your hair loss is due to iron deficiency, taking iron supplements may help. However, there is not enough evidence to prove that it promotes hair growth in the absence of iron deficiency.
selenium
Interestingly, too little or too much selenium can cause hair loss.
Dietary sources of selenium include:
The recommended dietary intake of selenium for adults is:
55 micrograms (mcg) daily 60 micrograms (mcg) daily during pregnancy 70 micrograms (mcg) daily while breastfeeding
Selenium has been studied in people who have lost hair due to chemotherapy. However, other vitamins were also taken during the trial, so their effectiveness is unknown.
Selenium has been studied at doses of 5 mcg/kg daily in infants with alopecia.
Hair loss is a common side effect of selenium toxicity (too much of it in the body). Therefore, supplementing with selenium for hair loss is not recommended if there are sufficient levels in the body.
Alopecia, or alopecia, affects almost half of people over the age of 50. It can be reversible or permanent. Reversible hair loss occurs when the hair cycle changes, but the hair follicles are not destroyed. Permanent hair loss occurs when scar tissue replaces hair follicles.
What conditions cause hair loss?
The following can cause hair loss:
What medicines cause hair loss?
Some medications can also cause hair loss. These include:
The appropriate treatment for hair loss depends on its cause.
What treatments are available for hair loss?
The FDA has approved the following hair loss treatments:
Hair transplantation, a type of surgery that regenerates hair, is also available.
summary
If you’re concerned about hair loss, a dermatologist can help determine the cause of your hair loss.
Many of the nutrients related to the hair cycle can be found in a healthy diet. Some people may be deficient in one of these, such as iron, zinc, or biotin. If you have low levels of any of these vitamins and minerals, supplementing with that nutrient may promote hair growth. However, if your body already has normal levels of these vitamins and minerals, these supplements are unlikely to treat or prevent hair loss.
Be aware that taking supplements you don’t need can do more harm than good and cause unwanted side effects or worsen your hair loss.
FAQ
Which supplements are best for promoting hair growth?
Some supplements, including collagen, peptides, lipids, and hyaluronic acid, have shown results in as little as 8 weeks of treatment. Ideally, head-to-head clinical trials are needed to compare multiple supplements.
Are there any supplements that are effective for hair growth?
Supplements such as vitamins and minerals are most effective for hair growth if your hair loss is due to a lack of nutrients.
Although there are case reports and anecdotes about the benefits of these supplements, there is not enough hard evidence to recommend them routinely.
What kind of diet promotes hair growth?
A Mediterranean diet may help hair growth.
This diet, which is low in meat and dairy products and high in fruits, vegetables, nuts, and fish, is associated with lower rates of hair loss. More clinical trials are needed to confirm this.
