Hair Regrowth

Last Updated: August 9, 2023

Hair regrowth refers to the rate of which hair grows, and may also refer to attenuating or reversing forms of alopecia (hair loss). These supplements can be both ingested or applied topically to the scalp.

What is hair loss?

Hair loss, also known as alopecia, refers to the loss of hair on the body. There are various types of hair loss, all of which tend to differ in their underlying causes, prevalence, and the pattern in which hair is lost. Common types of hair loss include male- and female-pattern hair loss (collectively referred to as androgenic alopecia; AGA), alopecia areata, telogen effluvium, and anagen effluvium.[35]

What are the main signs and symptoms of hair loss?

Male-pattern hair loss typically begins with hair loss at the front of the hairline and/or on the crown of the head, with hair loss progression over time.[36] Female-pattern hair loss tends to feature diffuse hair thinning and hair loss across the top of the head, especially near the center of the scalp.[36] Alopecia areata involves hair loss in patches, which can regrow or precede complete loss of hair. Telogen effluvium and anagen effluvium both involve hair thinning and hair loss across the scalp.

How is hair loss diagnosed?

A medical professional may use various methodologies to diagnose hair loss, including visual examination, medical history, biopsy, and laboratory testing.[37]

One test often employed is a hair pull test.[38] During this procedure, a small section of hair is grasped and gently pulled on, with the process repeated at various areas of the scalp. The number of hairs that come out upon pulling can indicate if hair loss is occurring and its severity. Additionally, examination of the hairs that fall out can help establish what type of hair loss is occurring.

What are some of the main medical treatments for hair loss?

The only two drugs currently approved by the FDA for the treatment of androgenic alopecia are minoxidil (used topically) and finasteride (taken orally).[35] Of these, minoxidil is approved for the treatment of both male- and female-pattern hair loss, while finasteride is only approved for men with male-pattern hair loss. Other treatments used for androgenic alopecia include dutasteride, prostaglandin analogs (e.g., latanoprost), injection with platelet-rich plasma, and anti-androgens (for women with hair loss due to high androgen levels).

The first-line treatment for alopecia areata is the injection of corticosteroids into sites of hair loss.[39]

Have any supplements been studied for hair loss?

Several RCTs have tested the effect of individual supplements on hair loss, given either orally (including vitamin E and saw palmetto) or applied topically to the scalp (including pumpkin seed oil, melatonin, and procyanidin from apples).[40] A number of studies have also examined the effect of oral supplements containing a mixture of compounds, typically a combination of nutrients (e.g., amino acids and vitamins).

What's the connection between diet and hair loss?

Research on the effect of diet on hair loss is very limited. One small case-control study found that men with high intakes of either raw vegetables or fresh herbs were less likely to have AGA.[41] In rare cases, certain nutrient deficiencies may lead to hair loss (especially in susceptible individuals), with one example being iron-deficiency anemia.[42]

Are there any other treatments for hair loss?

Low-level laser therapy (LLLT) involves the application of red and infrared light onto areas of the scalp, and available evidence indicates LLLT can prevent hair loss and potentially support hair regrowth in AGA.[43]

Microneedling (a procedure in which the skin is repeatedly punctured by a large number of very small needles) may be able to enhance the effects of minoxidil in preventing hair loss and producing hair regrowth in AGA.[44]

Ketoconazole is an antifungal medication that may reduce hair loss and potentially promote hair regrowth in AGA when applied to the scalp via medicated shampoo.[45]

What causes hair loss?

Male-pattern baldness is due in large part to an androgen (a so-called “male hormone") called dihydrotestosterone (DHT), which can sometimes contribute to female-pattern baldness as well. Other factors – like aging and genetics – can also increase the risk of male- and female-pattern baldness.

Alopecia areata is the result of the body's immune cells attacking hair follicles, resulting in inflammation and eventual hair loss.

Hair loss can also be the result of medical conditions, medications, and infection.

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  44. ^Robert S English Jr, Sophia Ruiz, Pedro DoAmaralMicroneedling and Its Use in Hair Loss Disorders: A Systematic ReviewDermatol Ther (Heidelb).(2022 Jan)
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Examine Database References
  1. Minoxidil - Berger RS, Fu JL, Smiles KA, Turner CB, Schnell BM, Werchowski KM, Lammers KMThe effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trialBr J Dermatol.(2003 Aug)
  2. Minoxidil - Arca E, Açikgöz G, Taştan HB, Köse O, Kurumlu ZAn open, randomized, comparative study of oral finasteride and 5% topical minoxidil in male androgenetic alopeciaDermatology.(2004)
  3. Saw Palmetto - Rossi A, Mari E, Scarno M, Garelli V, Maxia C, Scali E, Iorio A, Carlesimo MComparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year studyInt J Immunopathol Pharmacol.(2012 Oct-Dec)
  4. Minoxidil - Price VH, Menefee E, Strauss PCChanges in hair weight and hair count in men with androgenetic alopecia, after application of 5% and 2% topical minoxidil, placebo, or no treatmentJ Am Acad Dermatol.(1999 Nov)
  5. Vitamin E - Beoy LA, Woei WJ, Hay YKEffects of tocotrienol supplementation on hair growth in human volunteersTrop Life Sci Res.(2010 Dec)
  6. Minoxidil - Ulrike Blume-Peytavi, Kathrin Hillmann, Ekkehart Dietz, Douglas Canfield, Natalie Garcia BartelsA randomized, single-blind trial of 5% minoxidil foam once daily versus 2% minoxidil solution twice daily in the treatment of androgenetic alopecia in womenJ Am Acad Dermatol.(2011 Dec)
  7. Minoxidil - Olsen EA, Whiting D, Bergfeld W, Miller J, Hordinsky M, Wanser R, Zhang P, Kohut BA multicenter, randomized, placebo-controlled, double-blind clinical trial of a novel formulation of 5% minoxidil topical foam versus placebo in the treatment of androgenetic alopecia in menJ Am Acad Dermatol.(2007 Nov)
  8. Minoxidil - Tsuboi R, Arano O, Nishikawa T, Yamada H, Katsuoka KRandomized clinical trial comparing 5% and 1% topical minoxidil for the treatment of androgenetic alopecia in Japanese menJ Dermatol.(2009 Aug)
  9. Minoxidil - Lucky AW, Piacquadio DJ, Ditre CM, Dunlap F, Kantor I, Pandya AG, Savin RC, Tharp MDA randomized, placebo-controlled trial of 5% and 2% topical minoxidil solutions in the treatment of female pattern hair lossJ Am Acad Dermatol.(2004 Apr)
  10. Raspberry Ketone - Harada N, Okajima K, Narimatsu N, Kurihara H, Nakagata NEffect of topical application of raspberry ketone on dermal production of insulin-like growth factor-I in mice and on hair growth and skin elasticity in humansGrowth Horm IGF Res.(2008 Aug)
  11. Minoxidil - Olsen EA, Dunlap FE, Funicella T, Koperski JA, Swinehart JM, Tschen EH, Trancik RJA randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in menJ Am Acad Dermatol.(2002 Sep)
  12. Kefir - Gulbeyaz Can, Erkan Topuz, Duygu Derin, Zehra Durna, Adnan AydinerEffect of kefir on the quality of life of patients being treated for colorectal cancerOncol Nurs Forum.(2009 Nov)
  13. Magnesium - Jaripur M, Ghasemi-Tehrani H, Askari G, Gholizadeh-Moghaddam M, Clark CCT, Rouhani MHThe effects of magnesium supplementation on abnormal uterine bleeding, alopecia, quality of life, and acne in women with polycystic ovary syndrome: a randomized clinical trial.Reprod Biol Endocrinol.(2022-Aug-02)
  14. Red Light Therapy - Lueangarun S, Visutjindaporn P, Parcharoen Y, Jamparuang P, Tempark TA Systematic Review and Meta-analysis of Randomized Controlled Trials of United States Food and Drug Administration-Approved, Home-use, Low-Level Light/Laser Therapy Devices for Pattern Hair Loss: Device Design and Technology.J Clin Aesthet Dermatol.(2021-Nov)