Hair Growth Supplements: What Ingredients Should You Look For?
If you are experiencing thinning hair or increased shedding, you may have come across dozens of hair growth supplements promising thicker, stronger or healthier-looking hair.
But with so many products available, how do you know what ingredients to look for?
Hair supplements can contain a wide range of vitamins, minerals, amino acids, plant extracts and other nutrients. Some ingredients are important for normal nutrition and hair health, particularly when a person has a deficiency. However, taking more of a nutrient does not automatically mean faster or better hair growth.
Hair loss has many possible causes, including genetics, hormonal changes, stress, nutritional deficiencies, medical conditions and damage caused by hair-care practices. Identifying the underlying cause is therefore an important part of deciding whether a supplement is appropriate.
In this guide, we explain some of the most common ingredients found in hair growth supplements, what they do, what the evidence says and what to consider before adding a supplement to your routine.
What Are Hair Growth Supplements?
Hair growth supplements are oral dietary supplements formulated to provide nutrients or other ingredients marketed for hair health.
Depending on the product, a formula may contain ingredients such as:
- Biotin
- Zinc
- Iron
- Vitamin D
- Vitamin B12
- Folic acid
- Selenium
- Vitamin C
- Amino acids
- Omega-3 fatty acids
- Plant extracts
- Other antioxidant compounds
Not every ingredient is appropriate for every person.
For example, if hair loss is related to a nutrient deficiency, correcting that deficiency may be relevant. If the cause is genetic or hormonal, however, taking a general supplement may not address the underlying reason for the hair loss.
The American Academy of Dermatology recommends identifying the cause of hair loss and checking whether a person actually has a nutrient deficiency before taking supplements such as biotin, iron or zinc.
What Ingredients Should You Look For in Hair Growth Supplements?
There is no single ingredient that works for every type of hair loss.
Instead, it is useful to understand the role of individual nutrients and why they are included in supplement formulas.
1. Biotin
Biotin, also known as vitamin B7, is probably one of the most recognisable ingredients in hair supplements.
Biotin is a water-soluble B vitamin that helps the body process carbohydrates, fats and proteins.
Biotin deficiency can cause symptoms including hair thinning or hair loss. However, biotin deficiency is considered rare in people who eat a normal mixed diet.
The National Institutes of Health Office of Dietary Supplements notes that there is currently limited scientific evidence supporting biotin supplementation for improving hair health in people who are not deficient.
This distinction is important.
A supplement containing biotin should not automatically be considered a treatment for female pattern hair loss or other common forms of hair loss.
Why is biotin included in hair supplements?
Biotin is included because adequate biotin is necessary for normal body function and deficiency can be associated with hair loss.
However, more is not necessarily better.
High doses of biotin can interfere with certain laboratory tests and may produce falsely high or low results. This can be particularly relevant for some hormone and thyroid tests.
If you regularly take a high-biotin supplement, tell your doctor or healthcare professional before having blood tests.
2. Iron
Iron is another important nutrient to consider when discussing hair health.
Iron is involved in the production of haemoglobin and many other processes in the body. In some people, inadequate iron levels may be associated with hair loss.
However, taking iron without knowing whether yo
