Hair Growth: How to Make Hair Grow Thicker and Faster

Lots of things can affect hair growth and fullness, including age, genetics, diet, menopause and hormones, and certain medical conditions. Fortunately, there are several ways to promote hair growth and overall health at home. The key, however, is to be patient and allow proven ingredients enough time to work. Understanding how hair growth works will help you also understand why it can take time for hair growth products and supplements to start working, revealing fuller, healthier hair over time.

Each hair follicle you have grows a single strand of hair, using oxygen and nutrients supplied to it from the blood in your scalp. This hair growth process happens in four stages:

1. Anagen (growth) phase. The growth phase is the longest phase, lasting anywhere from 2 to 7 years. During this phase, hair follicles produce keratin-rich cells, which continue to form and grow the hair strand until it reaches the end of its growth phase. Because the anagen phase is the longest, around 90% of your hair will be in this stage at any given time (3).

2. Catagen (transition) phase. This is a much shorter phase, lasting around 10 days, and marks the transition from growth to resting. During the catagen phase, hair follicles begin to shrink and the hair starts to separate from the follicle.

3. Telogen (resting) phase. The resting phase lasts around three months. Like its name suggests, hair in this stage is at rest – it’s not actively growing, but it doesn’t fall out just yet, either.

4. Exogen (shedding) phase. The exogen phase is an extension of the telogen phase. During this phase, which lasts for several months, hair sheds from the follicle and a new strand begins to form. It’s normal to lose up to 100 hairs each day during this phase.

The goal of hair growth products is to nourish the scalp and hair follicles to encourage and prolong the growth phase of this cycle. The longer the anagen phase lasts, the longer your hair can grow. Some of the best hair growth ingredients for this purpose include:

• Biotin. Also known as vitamin B7, biotin is one of the most well-researched hair growth supplements. It promotes keratin production, which is a key protein used in the anagen phase to create new hair growth. 
  
• Keratin. Because keratin is the main protein found in your hair, products that have been properly formulated with this ingredient, such as  Viviscal Thin to Thick Shampoo , can help to reduce breakage and fortify hair strands, leading to stronger and thicker-looking hair.
  
• Saw palmetto. DHT (dihydrotestosterone )is a hormone that has been linked with hair loss and thinning by causing hair follicles to shrink (4). Saw palmetto is a palm-like plant with berries that has been shown to inhibit the production of DHT and therefore aid in hair growth and fullness (5). 
• Argan oil. Rich in omega-6 fatty acids and antioxidants, argan oil moisturizes and nourishes both the hair and scalp. It reduces dryness and promotes a healthy scalp environment that is needed for sustained hair growth.
• Vitamin E. A powerful antioxidant, vitamin E promotes circulation in the scalp, which helps to deliver essential nutrients to hair follicles. This improved blood flow can support healthier hair growth and protect against environmental stressors that can weaken hair.
  
• Green tea extract. The specific catechin in green tea, called EGCG (epigallocatechin gallate), has been shown to stimulate hair growth by encouraging cell proliferation within hair follicles. It may also help to reduce DHT levels, supporting hair density and preventing thinning (6).
• Lemon extract. The sinapic acid found in citrus fruits like lemons has been shown to promote hair growth by stimulating growth factors and deactivating a specific pathway called GSK-3β/β-catenin to keep hair follicles in the growth phase longer (7).

Hair growth and fullness relies on promoting scalp health and prolonging the anagen, or growth, phase of hair. Using topical or oral ingredients like biotin, keratin, saw palmetto, vitamin E, vitamin C, and others listed in this guide can help to significantly improve the health and appearance of your hair.

If you are struggling with conditions such as alopecia and have not had success with topical or oral supplements, talk to your dermatologist about in-office treatments like PRP therapy or laser therapy.

1. Baumann L. Antiaging Ingredients in Ch. 37 of Baumann's Cosmetic Dermatology Ed 3. (McGraw Hill 2022)
2. Baumann, L. Ch. Cosmeceuticals and cosmetic Ingredients (McGraw Hill 2015)
3. Burg D, Yamamoto M, Namekata M, Haklani J, Koike K, Halasz M. Promotion of anagen, increased hair density and reduction of hair fall in a clinical setting following identification of FGF5-inhibiting compounds via a novel 2-stage process. Clin Cosmet Investig Dermatol. 2017 Feb 27;10:71-85.
4. Urysiak-Czubatka I, Kmieć ML, Broniarczyk-Dyła G. Assessment of the usefulness of dihydrotestosterone in the diagnostics of patients with androgenetic alopecia. Postepy Dermatol Alergol. 2014 Aug;31(4):207-15. doi: 10.5114/pdia.2014.40925.
5. Evron E, Juhasz M, Babadjouni A, Mesinkovska NA. Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia. Skin Appendage Disord. 2020 Nov;6(6):329-337.
6. Zhang H, Nan W, Wang S, Song X, Si H, Li T, Li G. Epigallocatechin-3-Gallate Promotes the Growth of Mink Hair Follicles Through Sonic Hedgehog and Protein Kinase B Signaling Pathways. Front Pharmacol. 2018 Jun 26;9:674.
7. Woo H, Lee S, Kim S, Park D, Jung E. Effect of sinapic acid on hair growth promoting in human hair follicle dermal papilla cells via Akt activation. Arch Dermatol Res. 2017 Jul;309(5):381-388.