Supplements for healthier hair

Supplements for Hair
Danielle Kiser MS, RDN, CDN

Many products advertise benefits to skin, nail, and hair quality. If you’ve ever walked through a supplement aisle in Walmart or Walgreens you’ve likely been intrigued by certain claims. For instance a product that will “make you look younger”, “more beautiful”, “wrinkle free”, etc. Collagen and Biotin are just two of the common supplements out there claiming to give you thicker and healthier looking hair. But do they really work or are you just wasting your money? Even more importantly, could they be harming you?

It’s also important to note that an inadequate eating pattern cannot be “fixed” with supplements. As a dietitian, I have people tell me all the time that they “do not like fruits and vegetables” but don’t worry because they take “a bunch of dietary supplements”. If you aren’t meeting your needs with food first, any potential benefit a supplement could have had will likely be lost. So here is a review of current research on four common supplements and also teach you how to choose a high quality, safe supplement.


What is it? Biotin is a water-soluble vitamin. It has recently gained popularity by being advertised to support hair and nail growth/health. 

Foods with Biotin: Eggs, beans, nuts/seeds, carrots, sweet potatoes, etc. It is readily found in many foods in our food supply. Deficiency is extremely rare.

What Does Research Show? Although there is evidence showing some benefit to treat pathologic brittle hair syndrome or uncombable hair syndrome, it is thought to be unnecessary in generally healthy individuals. Biotin deficiency is extremely rare. There is little to no research to date to support improvement of hair or nail quality and/or quantity. The FDA doesn’t recommend daily biotin supplementation. An exception to this are pregnant or breastfeeding women who are advised to take 5-35 mcg/day due to pregnancy increasing the metabolism of biotin. 

Conclusion: Likely a waste of your money! To summarize, if you have an underlying condition or poor hair/nail growth or are pregnant, biotin supplementation may help. Otherwise, you are likely just wasting your money on biotin supplements. Instead, make sure you are eating a healthy balanced diet filled with vitamins, minerals, and lean proteins. 


What is Collagen? It is the major structural protein found in skin and connective tissues. It makes up 25-35% of all human protein in the body. It is widely known and used with the intent to improve the quality of skin, hair, and nails. There are different types of collagen, about 90% are type I collagen. As we age, we naturally slow down collagen production. Visible signs of this are wrinkles, sagging, bones growing weaker, and joint pain. The follicles in your hair are affected too. 

Hair follicles depend on collagen to keep them strong, hydrated, and supplied with nutrients. Hair that grows without enough collagen is dry, brittle, and dull colored. Plus, follicles can’t keep up with demand and produce less hair. Therefore, you are stuck with dry, brittle, dull, and thinner hair. Since hair isn’t a metabolic or biological need, hair is not top priority for nutrients. When you become deficient in a nutrient, your vital organs and other metabolic functions have priority. 

Food Sources: Animal proteins, more specifically the skin of animals are high in collagen. However, it is also high in saturated fat and calories. Plus foods that contain collagen don’t directly correlate to increased collagen in human bodies. For instance bone broth is thought to directly lead to a decrease in wrinkles, tighter skin, and thicker hair. There is little to no evidence showing this. So consuming foods that rather have the potential to boost collagen production is ideal. Foods such as cucumbers, beets, melon, and foods high in omega 3’s (i.e. salmon). These have the potential to make a difference, not copious amounts of bone broth or animal skins.

Is it Safe? Collagen supplementation is generally safe with no reported adverse events. You should always check with your doctor before starting any supplement and make sure it is a reputable brand/source. 

Conclusion: Not a complete waste of money! In summary, research has shown that collagen is connected with hair follicle health. Therefore, collagen can be used as a prevention and/or treatment for hair loss and has potential to improve hair quality. It is also a generally safe supplement with little to no side effects in healthy populations. 

Fish Oil

What is it / Food Sources? Fish oil can be obtained by eating fatty fish such as salmon, mackerel, herring and tuna. Or it can be obtained in supplement form. Supplemental form is especially popular in the United States where our population doesn’t tend to eat multiple (if any) servings of fatty fish per week. As a dietitian, this is one of the most common supplements I recommend. Some studies have shown long-term (>6-months) of supplementation with omega 3’s can prevent hair loss and improve hair density.

RD Tip: DO NOT consume fish oil supplements with a hot beverage (i.e. coffee or tea). You will be burping up fish taste for hours. Thank me later.

Is it Safe?: Fish oil supplements are generally; however do not take it if you are allergic to fish or soybeans. Fish oil also has the potential to slow blood clotting which in return can increase bleeding or bruising. This can be especially dangerous when taken with other medicines that slow blood clotting such as aspirin or ibuprofen. Again, consult with your doctor before starting fish oil supplements.

Conclusion: Not a waste of money! They have research to support hair and skin health. It’s also a nutrient often lacking in the American diet, therefore supplements can be beneficial in ways beyond hair health such as decreasing the risk of cancers, psoriasis, menstrual cramps, high blood pressure, and even osteoporosis. 


What is it? Zinc is a trace mineral involved in many different bodily functions including DNA, wound healing, growth and development, vision, and our ability to taste and smell. It has been known to be used for treating hair loss even without a diagnosis of “zinc deficiency”. Vegetarians and vegan are at higher risk of deficiency. Research has shown mixed results on zinc and hair health. It is dependent on the dosing as well as the timing. A study in mice found that short-term it can accelerate hair growth, but if taken for too long it can actually do the opposite and be counter-productive. 

Zinc Foods: Shellfish, beef, pork, chicken, breakfast cereal, oatmeal, baked beans, chickpeas, cashews, and dairy products.

RD Tip: Vegans and vegetarians are at higher risk of zinc deficiency due to the lack of animal products but also their diet high in legumes and whole grains. These foods contain strong antioxidants which interfere with zinc absorption. To combat this, soak beans, grains, and seeds a few hours before cooking and eat leavened vs. unleavened grain products. 

Is it Safe?: Long term zinc usage can lead to kidney failure due to cadmium, another metal that occurs naturally with zinc. If you are advised to take zinc, look for zinc gluconate which contains the lowest levels of cadmium. Zinc supplements also interfere with absorption of some medications such as Cipro and Tetracycline so advise with your MD.

Conclusion: Likely a waste of your money! To summarize, zinc supplementation should only be taken if prescribed by an MD and monitored under medical supervision. It’s not advisable for people to start popping zinc in an attempt to get thicker, healthier hair. Opt for eating a diet rich in zinc with the foods listed above. If you are prescribed to take zinc, opt for zinc gluconate and take the recommended dose and timing.

Choosing Safe Supplements

In general, supplements are loosely regulated in the United States. They are often tested and found to include varying amounts versus what is actually listed and/or include potentially harmful ingredients. To protect yourself and get the most “bang for your buck” look for these seals of approval: : The best known certification program that randomly tests for ingredients, strength, and contamination of supplements. Brands that pass their tests can have their seal of approval listed.

The U.S. Pharmacopeial Convention (USP) : An organization that sets standards for drug manufacturers. Additionally, it certifies supplements through their Dietary Supplement Verification Program.

NSF International: Another organization that evaluates supplements under its voluntary certification and testing program. If ingredient labels are accurate, there are good manufacturing practices in place, and no contaminants found then a supplement can have a NSF seal.


Choi FD, Sung CT, Juhasz ML, Mesinkovsk NA. Oral Collagen Supplementation: A Systematic Review of Dermatological Applications. J Drugs Dermatol. 2019;18(1):9-16.

Le Floc’h C, Cheniti A, Connétable S, Piccardi N, Vincenzi C, Tosti A. Effect of a nutritional supplement on hair loss in women. J Cosmet Dermatol. 2015;14(1):76-82. doi:10.1111/jocd.12127 Kang, J. I., Yoon, H. S., Kim, S. M., Park, J. E., Hyun, Y. J., Ko, A., Ahn, Y. S., Koh, Y. S., Hyun, J. W., Yoo, E. S., & Kang, H. K. (2018). Mackerel-Derived Fermented Fish Oil Promotes Hair Growth by Anagen-Stimulating Pathways. International journal of molecular sciences, 19(9), 2770. Biotin Review Article 

Cite: Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017;3(3):166-169. doi:10.1159/000462981

Bistas KG, Tadi P. Biotin. In: StatPearls. Treasure Island (FL): StatPearls Publishing; July 8, 2020.