Science-Backed Hair Regrowth Treatments | The Doctor Weighs In

By: Deanne Mraz Robinson, MD

There are many different types of science-backed hair regrowth treatments, including laser. Early intervention usually produces the best results.

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Photo source: iStock Photos

Male and female pattern hair loss, also known as androgenetic alopecia, is pervasive. An estimated 50 million men and 30 million women in the United States alone have this condition. Unfortunately, although it is prevalent, individuals affected by premature or unwanted hair loss often cover it up, ignore it, or delay treatment. Many don’t understand that many science-backed hair regrowth treatment options are available today. And, they are not sure which type of health care provider to confer with. Sometimes, they are simply too embarrassed to seek help.

The evolution of science-backed hair regrowth treatments

In the early days of hair growth product development, there were many roadblocks that hindered progress. These included the following:

  • A lack of well-designed rigorous clinical trials
  • A paucity of products that actually worked
  • Innumerable technology and laboratory cell culture challenges

It didn’t help that there were unsubstantiated claims about many products out in the market. That environment understandably made most scientists, physicians, and consumers extremely skeptical of any research related to hair regrowth.

What people want from hair regrowth treatments

Providing consumers with the information they need to make educated choices about hair growth options is the best way to mitigate skepticism. Based on my experience taking care of patients with hair loss, I believe that people want the following from a hair growth treatment program:

  • efficacy,
  • safety,
  • ease of use, and
  • discretion. Efficacy and safety top the list, but being able to easily incorporate the product or treatment into their daily routine is equally important.

Patients are also hungry for straight forward answers to basic questions about hair loss, such as:

  • what is the cause?
  • will it get worse?
  • will their children inherit it?
  • are there available treatments that work?

The most common form of hair loss — androgenetic alopecia — is hereditary, so yes it does run in families. This type of hair loss occurs in response to hormonal changes that cause hair follicles to shrink. Unless treatment is implemented to halt or slow hair loss or regrow hair, the hair loss will worsen.

What are currently available science-backed hair regrowth treatment options?

There are quite a few science-backed options currently available for the treatment of hair growth disorders. These include:

  • over-the counter-topical minoxidil
  • prescription oral finasteride
  • surgical hair transplant
  • platelet-rich plasma (PRP) injections
  • light and laser therapy treatments

Each will be discussed in turn.

Minoxidil is the only over-the-counter medication for patterned hair loss approved for use by men and women in the United States. Patients should know that Minoxidil takes at least 4 months to show visible effects. Further, the product must be used for at least a year to determine that it does not work for a given person.

All three formulations of minoxidil — 2% liquid solution, 5% liquid solution, and 5% foam — are effective. However, it is important to point out that stopping the medication can cause hair loss to resume.[2]

In my practice, I also use a lot of compounded topical minoxidil at higher concentrations — 7% to 10%. Oral minoxidil is also an option.

Finasteride is a prescription drug approved for men. Research shows that about 90% of men taking finasteride in pill form once daily stopped losing their hair and 65% had partial regrowth over 6 months.Finasteride users must keep taking it to retain benefits. Rare side effects include diminished libido and sexual dysfunction.

Hair transplant surgery has evolved significantly over the years. It is now an umbrella term that includes several methods including flap surgery, tissue expansion of the scalp, and scalp reduction surgery.

Hair transplantation and flap surgeries involve taking pieces of hair-bearing scalp from a donor site and using them as grafts on bald areas of the scalp. Tissue expansion surgery enables the hair-bearing scalp to be expanded to help cover areas of the scalp that have no hair, and scalp reduction surgery involves surgically removing bald areas of the scalp and then surgically connecting the hair-bearing areas of the scalp.

Platelet Rich Plasma (PRP) injections are another option that is gaining interest among patients. When platelet-rich plasma is activated, growth factors are released. They play a role in promoting wound healing and tissue regeneration and potentially stimulating hair growth.

PRP has demonstrated therapeutic effectiveness for androgenetic alopecia in 10 of 12 reviewed studies. A series of 3 treatments is typically recommended. Results are usually seen 3 to 6 months post-treatment.

Light therapy has been considered a developing technology in the hair growth arena for decades. It is now reaching the mainstream. Light therapy is referred to in several ways:

  • low-level laser therapy (LLLT)
  • low-level light therapy
  • photobiomodulation (PBM)

Regardless of the terminology, the idea is the same: It is the use of non-thermal, low-intensity light of specific wavelengths to trigger biochemical changes in the scalp.

Research suggests that when LLLT is applied to the scalp, it acts to increase the number of hair follicles as well as hair’s tensile strength. This is likely achieved through improved microvascular circulation, reduced inflammation, and increased cell energy in the form of adenosine triphosphatase (ATP).

Light therapy is an attractive option for patients in search of hair growth solutions — especially those who are interested in at-home treatment. Patients with patterned hair loss have impressive levels of success with at-home LLLT devices.

A brief history of light laser therapy devices

In 2007, the first at-home LLLT hair growth device — the HairMax Laser Comb-was cleared by the FDA. Patients using the comb had a greater increase in mean terminal hair density compared with those using a sham device. However, the device did not provide uniform light delivery and was also limited by weak patient adherence.

Laser helmets and caps were among the products that followed the laser comb, and research, as well as anecdotal experience, indicates that light delivered in a wearable helmet or cap resolves the dose uniformity issue. The literature supports an excellent safety profile as well as noteworthy efficacy claims for several of these cap and helmet devices, however long-term, high-quality studies comparing devices in diverse populations are needed to strengthen these claims.

There are now almost 50 devices on the FDA’s 510(k) premarket notification list that are classified as laser products intended for growth of scalp hair.

A new hair regrowth treatment device with a novel color combination

A standout on the list of cleared LLLT hair growth devices is REVIAN RED. It is an at-home device that uses a cap to deliver a novel color combination of dark orange (620 nm) and red light (660 nm).

This device has several noteworthy features:

  1. The user must activate the cap through a validated mobile app once daily for 10 minutes;
  2. It is the first all-LED hair growth device
  3. It stimulates more nitric oxide production in the scalp than other comparable devices.

The benefits of these features are that the app tracks and supports compliance. And, consistent use enhances efficacy. LEDs can irradiate a large area of tissue with minimal power. And, they are small enough to be adapted into flexible, lightweight, comfortable at-home wearable devices.The stimulation of nitric oxide leads to vasodilation and increased blood flow, which is associated with the renewal of cells that grow hair.

Clinical trial demonstrates the efficacy of REVIAN RED for hair regrowth

The results of a small, Revian-sponsored 26 week multi-center, randomized, double-blind clinical trial were presented as a poster at the Winter Clinical Dermatology Conference held in Hawaii January 17–22, 2020.

The researchers, led by Rodney Sinclair, Dermatologist at the University of Melbourne in Australia, randomized 81 individuals with androgenetic alopecia to receive either a dual-wavelength 620 nm and 660 nm light therapy device paired with a Bluetooth-connected mobile app (REVIAN RED System) or to a sham device providing a similar user experience. The participants were told to use the assigned device once a day for 10 minutes.

Eighteen patients in each group completed at least 16 weeks of treatment, were at least 80% compliant with the regimen and had no major protocol violations. When their scalps were examined at 16 weeks, compliant subjects treated with the Revian device had a mean change of 26.3 more hairs per cm² compared to those participants who wore the sham cap. There were no major adverse reactions in either group.

Two caveats about this study. It was funded by the company that makes the device and, although it was presented at a scientific meeting, it has not yet been subject to the type of peer-review scrutiny of an article published in a scientific journal.

I found the total hair count results and excellent safety profile reported in this trial encouraging. Further, I would be comfortable recommending it alone or in combination with other proven treatments, such as minoxidil or PRP.

It concerns me when I see so many patients who have lost years in their battle against hair loss by using ineffective treatments or no treatment at all. People concerned about hair loss should know that, in most cases, early intervention produces the best results.

Consulting an expert is a wise investment, and avoiding fads or non-science-based treatments is crucial. The best advice is to seek out a diagnosis from a board-certified dermatologist or other physicians who are well-versed in hair disorders.

Related article: Do You Really Need to Wash Your Hair with Shampoo


  2. Suchonwanit P, Thammarucha S, Leerunyakul K. Minoxidil and its use in hair disorders: a review. Drug Des Devel Ther. 2019;13:2777–2786. doi: 10.2147/DDDT.S214907
  3. Kaufman KD, Dawber RP. Finasteride, a Type 2 5alpha-reductase inhibitor, in the treatment of men with androgenetic alopecia. Expert Opin Investig Drugs. 1999;8(4):403–15. DOI:1517/13543784.8.4.403
  4. Cervantes J, Perper M, Wong LL, et al. Effectiveness of Platelet-Rich Plasma for Androgenetic Alopecia: A Review of the Literature. Skin Appendage Disord. 2018;4(1):1–11. doi:10.1159/000477671.
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  6. Leavitt M, Charles G, Heyman E, Michaels D. Clin Drug Invest. 2009;29(5):283–292. doi: 10.2165/00044011–200929050–00001.
  7. Erin M. Dodd, Margo A. Winter, Maria K. Hordinsky, Neil S. Sadick & Ronda S. Farah (2018) Photobiomodulation therapy for androgenetic alopecia: A clinician’s guide to home-use devices cleared by the Federal Drug Administration, Journal of Cosmetic and Laser Therapy, 20:3, 159–167.
  8. FDA 510(k) Premarket-Notification list of Laser, comb, hair devices; accessed January 24, 2020.
  9. Heiskanen V, Hamblin MR. Photobiomodulation: lasers vs. light-emitting diodes? [published correction appears in Photochem Photobiol Sci. 2018 Oct 31;:]. Photochem Photobiol Sci. 2018;17(8):1003–1017.
  10. Sinclair R, Murrell D, Spelman L, eta l. Clinical Safety and Efficacy of an At-Home, Dual Wavelength Red Light Hair Growth System in Subjects with Androgenetic Alopecia. Poster presented at 2020 Winter Clinical Dermatology Conference — Hawaii, Jan 21, 2020 (



Financial disclosures: Dr. Robinson is a speaker for Alastin, Cynosure, ISDIN and Merz and a consultant for Alastin, Allergan, Galderma, Merz, and Skinbetter Science

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Deanne Mraz Robinson, M.D., FAAD, is a board-certified dermatologist, co-founder of Modern Dermatology (the boutique practice in Westport, Connecticut), and a national and international lecturer on cosmetic and laser dermatology.

Dr. Robinson obtained her medical degree from the University of Rochester School of Medicine and Dentistry. She then went to complete her dermatology residency at Yale-New Haven Hospital in New Haven, CT, where she became chief resident. She then completed a fellowship in cosmetic, laser, and surgical dermatology at SkinCare Physicians in Chestnut Hill, MA.

She is an active member of several professional organizations. She also serves on advisory and leadership boards for the American Academy of Dermatology, the American Society of Dermatologic Surgery (ASDS), and the American Society for Laser Medicine and Surgery (ASLMS).

Dr. Mraz Robinson is an invited speaker at national surgical and aesthetic meetings, such as Controversies and Conversations, ASLMS, and ASDS. She remains active in academia and serves as volunteer faculty at Yale University of Medicine, Department of Dermatology.

Along with her distinguished experience in cosmetic dermatology, Dr. Mraz Robinson is active in research and has authored numerous articles for peer-reviewed journals and chapter texts, in addition to serving as an editor for multiple medical journals and audio publications such as Dialogues in Dermatology. She was one of the lead investigators in the FDA clearance trial for Cellfina and is thus one of the first physicians to treat cellulite with the minimally invasive Cellfina System. Additionally, she was one of the investigators in the pivotal approval trial for Kybella.

Originally published at on February 25, 2020.

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