Introduction
Hair loss—a topic that transcends vanity and touches our sense of identity. In midlife, this phenomenon can be particularly distressing. As we navigate the hormonal shifts of menopause, our once-lustrous locks may thin, leaving us pondering the science behind it all. Let’s unravel the role of hormones in the intricate dance of hair loss.
Androgens and Hair Loss: The Intricate Balance
Androgens play a crucial role in hair growth. Testosterone and 5α-dihydrotestosterone (DHT) are produced in the gonads (testes and ovaries), while 4-androstenedione (A4), dehydroepiandrosterone (DHEA), and its sulfate (DHEAS) are produced in the adrenal glands (1).
Testosterone and DHT are the most potent androgens for hair growth. Testosterone is converted into DHT by the enzyme 5α-reductase. Compared with testosterone, DHT binds even more tightly to the androgen receptor (1).
Although DHT promotes hair growth in the armpits and groin, excess levels can cause hair loss on the scalp (1).
1. Androgen Excess: The Usual Suspect
Understanding Androgenetic Alopecia/Female Pattern Hair Loss (FPHL)
In FPHL, hair follicles undergo a gradual transformation. Once robust and pigmented, they shrink, resulting in thinner, shorter hairs. DHT binds to androgen receptors in susceptible follicles, triggering this miniaturization process (1). Women experiencing hair loss often exhibit central scalp hair density reduction while preserving the frontal hairline. This presents as mid-scalp expansion and a frontal accentuation (resembling a Christmas tree).
FPHL is often attributed to elevated androgens. As evidence of that, FPHL and is reported in 42.5% of women with PCOS compared to 6% of the general female population. PCOS is a disorder of excess androgens, and other signs of PCOS include irregular periods, excess body hair, and acne (1).
However, FPHL should not be considered a sign of hyperandrogenism in the setting of normal androgen levels (2). When FPHL is due to estrogen deficiency, women typically show less frontal thinning and increased hair strength after 6 months of hormone therapy with estrogen. Hormone therapy improves the estrogen-to-androgen ratio and oral estrogen in particular inhibits androgen activity (1).
Treatment
First-line treatment for FPHL is 5% minoxidil, a non-hormonal vasodilator, which reduces hair loss by 56.6% (1). Oral minoxidil can also be considered, starting at 0.625 mg to 1.25 mg daily and increasing to 2.5 to 5mg over the course of 1 to 3 months. After an initial shedding of hair known as the "dread shed", it can take 4 to 6 months to see the maximal affect.
Oral antiandrogens like spironolactone, a diuretic, or bicalutamide. Spironolactone is an androgen receptor antagonist and also decreases total testosterone by blocking the synthesis of testosterone in the adrenals. At doses of 25-200 mg, it reduces hair loss by 43.2%. Bicalutamide at 10-50 mg daily reduces hair loss by 24.5% at 1 year, with a more favorable safety profile (1). Spironolactone and bicalutamide have both been shown to reduce libido in some users, with lower doses typically having a smaller effect on libido.
Minoxidil plus spironolactone 100-200 mg daily reduces hair loss by 65.8% (1). However, spironolactone may cause additional side effects such as low blood pressure, urinary frequency, and reduced libido.
5α-reductase inhibitors like finasteride 5 mg daily or dutasteride 0.5 mg daily reduce the conversion of testosterone into DHT (1). These drugs have been associated with sexual dysfunction and mood changes.
Application of topical retinoids, such as adapalene or tretinoin, prior to minoxidil has been found to improve the absorption and effect of minoxidil on hair loss (3).
Topical androgen receptor inhibitors like clascoterone and pyrilutamide, currently under development as of August 2024, are placed directly on the scalp (1).
2. Androgen Deficiency: A Surprising Twist
Testosterone During Perimenopause
As women approach menopause, testosterone levels may decline. Decreased androgen circulation can also lead to hair loss. After natural shedding occurs, there’s insufficient regrowth to replace the lost hair.
Treatment
One small study found that testosterone levels were significantly lower in women reporting hair loss prior to testosterone replacement, and 63% of those with hair thinning reported regrowth after treatment with testosterone (4). More study is needed in this area.
In summary, the relationship between androgens and hair loss is multifaceted. While excess androgens (like DHT) are often implicated, low androgens during menopause can also play a role. Our hair follicles respond to this delicate hormonal dance, and understanding these mechanisms helps us unravel the mystery of hair loss.
Stress, Cortisol, and Hair
The main stress hormones are corticotropin-releasing factor (CRF) from the hypothalamus, adrenocorticotropic hormone (ACTH) from the pituitary, and cortisol from the adrenal gland. Under stress, CRF binds directly to the hair follicle, prevents hair shaft elongation, and may directly lead to hair loss, although this continues to be investigated (1).
If this is suspected, salivary diurnal cortisol slope testing can be considered and possibly, in the future, hair cortisol concentration testing (1).
Treatment
Topical 2% ketoconazole shampoo may help block cortisol synthesis in the hair follicle and can be considered as an alternative to finasteride and minoxidil (1).
Thinning Due to the Thyroid
Hypothyroidism (low thyroid)
Low thyroid hormone decreases cell division in the hair follicle (1). 31% of individuals with FPHL have hypothyroidism. The directional cause of this association is unclear (1).
Hyperthyroidism (high thyroid)
High thyroid hormone causes oxidative damage in the hair follicle and can cause diffuse hair thinning (1).
Autoimmune Thyroid Disorders
A significant portion of patients with hair loss have evidence of thyroid antibody activity and thyroid hormone dysregulation (1).
Treatment
Regulation of thyroid hormones with thyroid replacement or antithyroid drugs typically resolves thyroid-related hair loss within a matter of months. However, antithyroid medications for hyperthyroidism may also cause hair loss (1).
Growth Hormone and Hair Growth
Although growth hormone (GH) has been found in hair follicles, its role isn’t clearly understood. Primary decreases in GH and IGF-1 are associated with frontal hairline recession (1).
Prolactin and Hair Loss: Another Piece of the Puzzle
Prolactin also plays a role in hair follicle growth and cycling. Elevated levels can cause hair loss (5). The relationship between prolactin levels and adrenal cortisol (a stress hormone) is still being discovered. Elevated prolactin levels have also been associated with seizure disorder, Parkinson’s disease, and multiple sclerosis (5).
Conclusion: Clinical Considerations and Treatment
Clinical Assessment
Diagnosing hair loss involves detective work. Look for patterns: overall thinning, easy breaking, receding hairline, increasing frontal part, or loss at the crown. If a hormonal cause of hair loss is suspected, consider checking LH, FSH, estradiol, testosterone, DHEAS, A4, SHBG, 17-OHP, prolactin, and TSH between days 2 and 5 of the menstrual cycle (1). But don’t stop there—consider vitamin D, anemia, and zinc levels (2). These backstage players might influence the plot.
Treatment Strategies
Stress Management
Hair follicles are well-known to respond to stress. Hair follicles can create cortisol and prolactin, two stress hormones. Stress management may include therapy, yoga, tai chi, guided meditation, and hypnosis.
Supplements
Saw palmetto: Saw palmetto blocks the activity of DHT in three ways. It limits the conversion of testosterone into DHT, blocks DHT binding to androgen receptors by 50%, and hastens the breakdown of DHT into metabolites. Among patients with AGA, hair density increased in 83.3% of those taking saw palmetto. Of note, saw palmetto has been reported to cause hot flashes in premenopausal women (6).
Pumpkin seed oil: Pumpkin seed oil, which also blocks 5α-reductase, can be used orally or topically (1).
Adequate Protein Intake
Protein is essential for hair growth as hair follicles are made mostly of protein. Ensuring adequate protein intake can help maintain healthy hair. Some good sources of protein include:
Lean meats: Chicken, turkey, and lean cuts of beef.
Fish: Salmon, mackerel, and other fatty fish rich in omega-3 fatty acids.
Eggs: A great source of protein and biotin, which is important for hair health.
Dairy products: Milk, yogurt, and cheese.
Legumes: Beans, lentils, and chickpeas.
Nuts and seeds: Almonds, walnuts, and chia seeds.
Soy products: Tofu, tempeh, and edamame.
Other Nutritional Recommendations
Iron: Iron deficiency can lead to hair loss. Include iron-rich foods such as spinach, lentils, and red meat in your diet. Of note, calcium and caffeine can decrease iron absorption while vitamin C can increase iron absorption.
Zinc: Zinc plays a crucial role in hair tissue growth and repair. Foods rich in zinc include oysters, beef, and pumpkin seeds. 1% pyrithione zinc shampoo has also been shown to aid in hair growth (7).
Vitamin D: Vitamin D is important for hair follicle cycling. Ensure adequate sun exposure and consider vitamin D supplements if needed.
Omega-3 fatty acids: These fatty acids help nourish the hair and support thickening. Include sources like fish oil, flaxseeds, and walnuts.
Biotin: Biotin (vitamin B7) is essential for hair health. Foods rich in biotin include eggs, almonds, and sweet potatoes. Biotin supplements can affect certain lab results including TSH, and should be held for 2 to 5 days prior to a lab draw.
Platelet-Rich Plasma (PRP) for Hair Loss:
What Is PRP? PRP is a treatment derived from a person’s own blood. It involves drawing a small amount of blood, processing it to concentrate the platelets, and then injecting the platelet-rich plasma back into the scalp. Platelets contain growth factors that may promote tissue repair and regeneration.
How Does PRP Work for Hair Loss? The idea behind PRP for hair loss is that the growth factors in platelets can stimulate hair growth by promoting blood flow and increasing the number of hair follicles. In addition, minimal side effects have been reported (8).
Conclusion: While some studies have shown promising results, PRP treatments are expensive, and outcomes are not guaranteed.
Red Light Therapy for Hair Loss:
What Is Red Light Therapy? Red light therapy (also known as low-level laser therapy or photobiomodulation) uses low levels of red light to target skin and cells. It is hypothesized to help with hair growth by reducing oxidative stress and decreasing inflammation (8).
Benefits: Several studies have shown improved hair growth and hair follicle diameter with red light therapy. One study that compared minoxidil and red light therapy found similar improvements. However, other studies have shown mixed results (8).
Devices: Red light therapy devices come in various forms, including masks, beds, panels, and handheld wands.
Microneedling
Microneedling has been shown to increase blood flow in the skin, and several studies have found improvement in hair growth when combined with topical minoxidil or dutasteride (8).
Lifestyle Recommendations
Regular Exercise: Exercise improves blood circulation, including to the scalp, which can promote hair growth.
Hydration: Staying well-hydrated is important for overall health, including hair health.
Avoid Smoking: Smoking can negatively impact blood circulation to the hair follicles, leading to hair loss.
Limit Heat Styling: Excessive use of heat styling tools can damage hair. Try to limit their use and always use a heat protectant.
Gentle Hair Care: Use a gentle shampoo and conditioner, and avoid harsh treatments that can damage hair.
Scalp Massage: Regular scalp massages can improve blood circulation to the hair follicles and promote hair growth (9).
Avoid Tight Hairstyles: Traction alopecia is hair loss caused by repeatedly pulling on the hair. This condition is often seen in individuals who frequently wear tight hairstyles such as ponytails, braids, or buns. The constant tension on the hair follicles can lead to inflammation and damage, resulting in hair loss.
Change Hairstyles Frequently: Opt for looser hairstyles that do not put excessive tension on the hair. Avoid wearing the same tight hairstyle every day to reduce stress on the hair follicles.
Use Gentle Hair Accessories: Choose hair ties and clips that do not pull on the hair excessively.
Remember, consult with a healthcare professional for personalized advice tailored to your unique situation. And may your hair journey be as resilient as your spirit! ✨
References:
Owecka B, Tomaszewska A, Dobrzeniecki K, Owecki M. The Hormonal Background of Hair Loss in Non-Scarring Alopecias. Biomedicines. 2024 Feb 24;12(3):513. doi: 10.3390/biomedicines12030513. PMID: 38540126; PMCID: PMC10968111.
Carmina E, Azziz R, Bergfeld W, Escobar-Morreale HF, Futterweit W, Huddleston H, Lobo R, Olsen E. Female Pattern Hair Loss and Androgen Excess: A Report From the Multidisciplinary Androgen Excess and PCOS Committee. J Clin Endocrinol Metab. 2019 Jul 1;104(7):2875-2891. doi: 10.1210/jc.2018-02548. PMID: 30785992.
Sharma A, Goren A, Dhurat R, Agrawal S, Sinclair R, Trüeb RM, Vañó-Galván S, Chen G, Tan Y, Kovacevic M, Situm M, McCoy J. Tretinoin enhances minoxidil response in androgenetic alopecia patients by upregulating follicular sulfotransferase enzymes. Dermatol Ther. 2019 May;32(3):e12915. doi: 10.1111/dth.12915. Epub 2019 Apr 23. PMID: 30974011.
Glaser RL, Dimitrakakis C, Messenger AG. Improvement in scalp hair growth in androgen-deficient women treated with testosterone: a questionnaire study. Br J Dermatol. 2012 Feb;166(2):274-8. doi: 10.1111/j.1365-2133.2011.10655.x. Epub 2012 Jan 9. PMID: 21967243; PMCID: PMC3380548.
Langan EA. Prolactin: A Mammalian Stress Hormone and Its Role in Cutaneous Pathophysiology. Int J Mol Sci. 2024 Jun 28;25(13):7100. doi: 10.3390/ijms25137100. PMID: 39000207; PMCID: PMC11241005.
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. doi: 10.1159/000509905. Epub 2020 Aug 23. PMID: 33313047; PMCID: PMC7706486.
Berger RS, Fu JL, Smiles KA, Turner CB, Schnell BM, Werchowski KM, Lammers KM. The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial. Br J Dermatol. 2003 Aug;149(2):354-62. doi: 10.1046/j.1365-2133.2003.05435.x. PMID: 12932243.
Huang X, Zhao P, Zhang G, Su X, Li H, Gong H, Ma X, Liu F. Application of Non-Pharmacologic Therapy in Hair Loss Treatment and Hair Regrowth. Clin Cosmet Investig Dermatol. 2024 Jul 23;17:1701-1710. doi: 10.2147/CCID.S471754. PMID: 39071847; PMCID: PMC11283242.
English RS Jr, Barazesh JM. Self-Assessments of Standardized Scalp Massages for Androgenic Alopecia: Survey Results. Dermatol Ther (Heidelb). 2019 Mar;9(1):167-178. doi: 10.1007/s13555-019-0281-6. Epub 2019 Jan 22. PMID: 30671883; PMCID: PMC6380978.
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