By Deep Shukla — Fact checked by Alexandra Sanfins, Ph.D.
A recent systematic review published in the journal JAMA Dermatology synthesized data from previous research, including randomized clinical trials, on nutritional supplements that could treat hair loss.
The study found that an array of supplements ranging from pumpkin seed oil, zinc, vitamin E, omega fatty acids, and certain commercial formulations like Viviscal and Nutrafol, among others, showed promise in the treatment of specific types of hair loss.
The studies included in the review were generally small and used subjective inclusion criteria, emphasizing the need for larger, more robust randomized clinical trials.
Common types of hair loss
The hair growth cycle can be divided into three phases. The first phase, known as anagen, is characterized by the growth of hair and can last several years.
Around 85–90% of hair follicles in a normal scalp are in the anagen or growth phase. The growth phase is followed by catagen, the transition phase involving the slowing of hair growth.
The catagen phase lasts about 14 days and is followed by the telogen or resting phase which lasts 3–4 months. Hair growth remains dormant during the resting phase and is followed by hair shedding. A loss of about 50–100 hair strands normally occurs every day.
Hair shedding in excess of these normal values is referred to as hair loss or alopecia.
Hair loss can occur due to many reasons, including genetics, aging, autoimmune disease, hormonal changes, and stress. Some of the common types of hair loss include androgenetic alopecia, alopecia areata, and telogen effluvium.
Androgenetic alopecia, referred to as pattern baldness, is the most common cause of hair loss that is estimated to affect 50% of men and women by the time they reach the age of 50 years. Alopecia areata, another common form of hair loss, is an autoimmune disease that results in the loss of small patches of hair.
Telogen effluvium is characterized by hair follicles prematurely exiting the growth phase and entering the telogen phase. This results in excessive shedding of hair in the resting phase.
Telogen effluvium often appears in response to stress, illness, or the use of medications.
Use of nutritional supplements
Treatment of hair loss generally requires addressing the underlying cause, such as nutritional deficiency or disease. There are also Food and Drug Administration (FDA)-approved medications for androgenetic alopecia, namely oral finasteride and topical minoxidil.
Due to the potential negative effects of finasteride in females, only minoxidil is also used for androgenetic alopecia in females.
However, both drugs are associated with adverse effects that may result in the discontinuation of their use. Specifically, finasteride can cause sexual dysfunction in men, whereas minoxidil is associated with dermatitis.
More recently, the FDA also approved baricitinib, a drug that modulates the immune system, for the treatment of severe alopecia areata.
Given the potential side effects associated with pharmacological treatments, there has been an interest in the use of alternative therapies, including nutritional supplements, for hair loss.
A recent study involving patients from a hair loss clinic showed that nearly 80% of individuals used nutritional supplements. However, there are limited data on the safety and efficacy of these supplements.
In the present study, the researchers summarized evidence from 30 prior human studies, including 17 randomized clinical trials, examining the effectiveness of various nutritional supplements in the treatment of hair loss.
They excluded studies involving hair loss due to nutritional deficiency, use of medications, trauma, or physical stress.
The researchers also categorized the studies according to the quality of evidence, with randomized clinical trials representing the highest level of evidence in the review.
Vitamins and antioxidants
Studies suggest that various types of hair loss, including alopecia areata, androgenetic alopecia, and telogen effluvium, are associated with oxidative stress and a deficiency of micronutrients such as vitamins.
While the review found some high-quality evidence to suggest that zinc could enhance hair growth in individuals with hair loss, evidence supporting a role for vitamin D and vitamin B12 in the treatment of hair loss was of lower quality.
Although biotin (vitamin B7) is a common ingredient in hair loss therapies, there was an absence of studies examining the effects of biotin as a standalone treatment.
However, results from randomized clinical trials suggest that tocotrienols, antioxidant compounds belonging to the vitamin E family, and a combination of fish oil (omega-3 and omega-6), blackcurrant seed oil, and antioxidants such as vitamin E and lycopene, could improve hair density in individuals with hair loss.
Hormone modulators, immunomodulators
Androgenetic alopecia is associated with the excessive response of hair follicles to an androgen called dihydrotestosterone (DHT), which is derived from testosterone.
Among nutritional supplements that inhibit the formation of DHT, data from a randomized clinical trial suggests that pumpkin seed oil could stimulate hair growth in men.
A deficiency of other hormones, such as insulin-like growth factor-1 (IGF-1), is also associated with hair loss. Studies suggest that capsaicin, the active ingredient in chili peppers, and isoflavones, a subclass of antioxidant compounds, could potentially increase the levels of insulin-like growth factor-1.
In addition, a small randomized clinical trial showed that capsaicin and isoflavones together can enhance hair growth in individuals with alopecia.
Plant-based compounds that can modulate the immune response, such as glycyrrhizin (licorice) and extracts from the peony plant, have also shown promise in the treatment of individuals with alopecia areata, which is characterized by an immune response against hair follicles.
Similarly, studies also suggest that procyanidin B-2, an anti-inflammatory and antioxidant compound, derived from certain apple species, can also stimulate hair growth.
Multi-ingredient commercial formulations
Pantogar includes keratin, the major protein in hair, and its building block L-cysteine, which could help promote hair growth.
Viviscal and Nourkirn contain proteins derived from marine animals that can facilitate hair growth. Nutrafol contains DHT synthesis blockers, antioxidants, and anti-inflammatory compounds, whereas Lambdapil contains L-cysteine, plant-derived silicon, and DHT synthesis blockers.
There is a lack of sufficient or high-quality evidence to support the role of other multi-ingredient commercial formulations such as Omni-Three and FORTI-5 in stimulating hair growth.
Besides having beneficial effects on hair growth, the interventions reviewed in the current study generally had mild side effects. These results suggest that nutritional supplements could potentially help treat certain types of hair loss.
However, the authors noted that the studies included in the review had several limitations. For instance, a majority of studies had a small sample size or used subjective reports of hair loss at baseline.
The authors also cautioned that some of the studies included in the review were funded by manufacturers of the nutritional supplements
The authors further noted concerns about the lack of FDA regulations that cover the efficacy, safety, and quality of supplements. Thus, nutritional supplements could potentially contain inefficacious or adulterated ingredients, with the latter resulting in side effects.
This requires dermatologists to work with patients to weigh the risks and benefits of such nutritional supplements.
Dr. Justin Rome, founder of the Barber Surgeons Guild, commented for Medical News Today that:
“While nutritional deficiencies can lead to hair loss, supplementation of vitamins such as biotin to those who are not deficient has not been shown to promote hair growth. Other novel ingredients may have a beneficial result in certain circumstances; however, they also may have no result or worse, potential adverse effects. It is important to note that nutritional supplements are not regulated by the FDA, which means they do not undergo the rigorous safety and efficacy testing as medications.”
“Be careful when choosing supplements, look for high-quality clinical trials supporting their use. High doses of certain nutrients can actually be harmful for example excess Selenium, can lead to toxicity and even worsen hair shedding, and high dose biotin can trigger acne and interfere with blood tests, so it’s important to do your research before you buy.”
Maintaining a healthy diet could also play a critical role in preventing hair loss. Dr. Reid Maclellan, founder and CEO of Cortina, and adjunct faculty at Harvard Medical School, told us that “[i]ncreasing your intake of protein and iron in your diet can help prevent hair loss in both men and women.”
“Iron deficiency or being anemic is the most evident factor that can lead to hair loss as it can affect the follicles from producing proteins to make the hair grow,” he added.
“Some foods that you can incorporate into your diet that can help add to your hair loss prevention plan include bone broth, eggs, seaweed/ kelp, seeds (flax, sunflower, chia), fish oils, and berries. Avoid alcohol, sugar, and processed foods which are DHT blockers,” advised Dr. Maclellan.
This article originally appeared here and was republished with permission.