How Stress & Hormonal Imbalances Cause Hair Loss
- Dr. Kam Tecaya
- Apr 21
- 13 min read
Excessive hair loss is a common concern that affects a significant portion of the global population. By the age of 50, more than 25% of women experience female pattern hair loss.¹ Over a lifetime, up to 80% of men and 50% of women will be affected by male pattern hair loss.² Given its prevalence, it’s no surprise that many patients present to healthcare providers with hair loss as a primary complaint.
Although not life-threatening, hair loss can have a profound impact on psychosocial well-being and overall quality of life.³˒⁴ It can lead to feelings of self-consciousness, frustration, jealousy, emotional distress, psychological disturbance, and embarrassment.⁴
Because hair growth and maintenance are closely influenced by free steroid hormone levels—including estrogen, progesterone, cortisol, dihydrotestosterone (DHT), and testosterone—salivary hormone testing can provide valuable clinical insight when evaluating the root causes of hair loss.
Understanding Healthy Hair Growth
To better understand how hormonal imbalances contribute to hair loss, it helps to first review the natural hair growth process. Even with optimal hormone levels and healthy hair growth, it is normal for both men and women to shed between 50 and 150 hairs per day.⁵˒⁶ At any given time, approximately 100,000 hairs are present on the scalp, each in a different stage of the growth cycle.²˒⁷
Hair itself is composed mainly of dead, keratinized cells, forming a filamentous structure. It consists of two main parts: the hair shaft, which is visible above the skin, and the hair follicle, which resides below the skin’s surface.
The Hair Growth Cycle
Each hair follicle undergoes a cyclical process consisting of four main phases: anagen, catagen, telogen, and exogen, as illustrated in the image below.⁷˒⁸
Anagen Phase (Growth Phase):This is the active growth phase, lasting between 2 to 8 years, with an average duration of about 3 years.⁶˒⁷ Approximately 90% of hairs on a healthy scalp are in the anagen phase at any given time. During this phase, rapid cell division occurs in the hair bulb matrix, promoting hair production and elongation.⁷
Catagen Phase (Transition Phase):This brief transitional stage marks the end of active hair growth. Hair follicle activity slows, and the lower part of the follicle begins to regress. The catagen phase typically lasts 2 to 3 weeks and affects less than 1% of scalp hairs.⁶⁻⁸
Telogen Phase (Resting Phase):Lasting approximately 2 to 5 months, this phase is a period of rest before the hair is shed.⁷ Around 9% of scalp hairs are in the telogen phase in healthy individuals.⁶
Exogen Phase (Shedding Phase):Sometimes referred to as teloptosis, this is when the hair is released and falls out.⁶˒⁷˒⁹
Following exogen, there is a period known as kenogen—the interval between the shedding of the old hair and the emergence of a new one from the follicle.⁷
Hormonal Hair Loss: Shifts in the Anagen-to-Telogen Ratio
Healthy hair growth depends on a delicate balance of several hormones. Disruption in a single hormone—or an imbalance among multiple hormones—can significantly impact the hair growth cycle. Key steroid hormones involved include androgens, estrogens, progesterone, and cortisol.
In a healthy scalp, the anagen-to-telogen ratio typically ranges from 12:1 to 14:1, meaning for every hair in the resting (telogen) phase, there are 12 to 14 actively growing hairs.⁶ However, hormonal imbalances can drastically shift this ratio:
In androgenetic alopecia (commonly referred to as male or female pattern hair loss), the ratio drops to 5:1, resulting in noticeably thinner hair density.⁶
In telogen effluvium (TE), a condition characterized by excessive shedding often triggered by stress, the ratio may shift to 8:1, causing shedding well beyond the normal 50–150 hairs per day.⁵˒⁶
Testosterone, DHT & Hair Loss – Understanding Androgenetic Alopecia (Male Pattern Baldness)
Testosterone is a key androgen hormone essential for healthy hair growth. However, its effects vary depending on the location of hair on the body. For example, hair follicles on the face, underarms, chest, and groin are stimulated by androgens.⁸ During puberty, increased androgen levels—particularly testosterone—convert soft, fine vellus hairs into thick, coarse terminal hairs, such as those in the beard area.¹⁰
In contrast, scalp hair follicles tend to be inhibited by elevated androgen levels.⁸ This paradoxical effect explains why androgens can contribute to hair growth in some areas while triggering hair loss in others.
Androgen hormones influence hair growth by interacting with intracellular androgen receptors located within hair follicle cells. When testosterone and its more potent derivative dihydrotestosterone (DHT) bind to these receptors, they alter gene expression, leading to changes in the hair growth cycle.⁸
In addition to their role in follicle regulation, androgens are also necessary for the production of sebum, an oily substance that moisturizes and protects the hair and scalp. At balanced levels, androgens help maintain healthy hair. However, excessive androgen activity, particularly involving DHT, can disrupt the natural hair cycle and shrink hair follicles—a hallmark of androgenetic alopecia, also known as male pattern baldness.¹⁰ This condition is one of the most common causes of chronic and excessive scalp hair loss.
The Role of DHT and Kenogen in Androgenetic Alopecia
Doctors and researchers widely agree that androgenetic alopecia—commonly known as male pattern baldness—is primarily driven by imbalances in androgen hormones, particularly dihydrotestosterone (DHT). Elevated levels of free DHT have been shown to shorten the anagen (growth) phase of the hair cycle, disrupting healthy hair development.¹⁰
High androgen levels also affect a lesser-known phase of the hair cycle called kenogen—the interval between when a hair sheds and a new hair begins to grow in its place. In healthy individuals, kenogen affects approximately 10% of scalp hair follicles and typically lasts about two months. However, in men with androgenetic alopecia, kenogen can extend to 4–7 months and affect up to 80% of hair follicles, significantly delaying new hair growth.¹¹
In women with androgenetic alopecia, research shows that kenogen affects about 22% of hair follicles, and both the frequency and duration of kenogen increase with the severity of hair loss. In one study, the kenogen phase in affected women lasted between 3 months and 1 year.¹¹
Over time, as the anagen phase shortens and kenogen lengthens, the affected follicles progressively shrink and begin to produce shorter, thinner, and softer hairs—a hallmark of androgen-driven scalp hair loss.¹⁰
Despite recent advances, many mechanisms by which androgen hormones affect hair follicles across different regions of the body remain incompletely understood. Ongoing research is essential to further clarify these complex interactions.⁸
Stress Hormones (Cortisol) and Hair Loss
Yes, stress can contribute to and be an underlying cause of concerning hair loss. Telogen effluvium is the medical name for the transient hair loss caused by a significant stressor.12 The stressor could be emotional or physical, such as major surgery or a divorce.
When stress is experienced, the hypothalamic-pituitary-adrenal (HPA) axis responds via the production of several hormones, including corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and ultimately, cortisol, the well-known steroid stress hormone.
According to research, stress hastens the anagen-to-telogen transition and elongates the telogen phase.6 Corticotropin-releasing hormone (CRH) is the non-steroid hormone released by the hypothalamus to stimulate the function of the entire hypothalamic-pituitary-adrenal (HPA) axis in response to stress. Therefore, individuals under the effects of stress often have high levels of CRH.8
Analysis shows both CRH and CRH receptors are present in the skin, and CRH inhibits hair growth, prematurely stimulates the catagen phase, and reduces the proliferation of keratinocytes, which are the cells that produce the keratin incorporated into the hair matrix. CRH can also alter the expression of genes to affect hair growth.8
As the first hormone released along the HPA axis, CRH also regulates the production of adrenocorticotropic hormone (ACTH) by the anterior pituitary gland. ACTH stimulates the adrenal glands to produce cortisol and androgen hormones. Animal studies suggest ACTH may also induce the anagen phase, but the role ACTH plays in hair growth requires further study and is still unclear.8
As one of the last hormones produced along the HPA axis, cortisol affects the cyclical regulation of the hair cycle and the synthesis of proteoglycans.6,3 Optimal proteoglycan synthesis is required for healthy hair growth.6
Proteoglycans include decorin and versican. Research shows versican protects cells in the hair follicle from cell death (apoptosis) due to oxidative stress. Decorin promotes hair growth by inducing the anagen phase.6 The high cortisol levels caused by stress can damage the proteoglycans in the hair follicles.6
Cortisol can also indirectly affect hair growth because high cortisol levels decrease the synthesis of insulin-like growth factor (IGF-1).13 IGF-1 is a non-steroid hormone that is the key signal responsible for the stimulation of hair follicle growth.8
Also, men and women with androgenetic alopecia often have higher cortisol levels in comparison to healthy individuals, suggesting both androgens and stress hormones may contribute to the development of male pattern baldness.6 The effect of stress on skin and hair is so significant that Arck et al. proposed a “brain-skin connection” theory to describe the link. The brain and skin, including hair follicles, are affected by many of the same neurotransmitters, neuropeptides, neurohormones, and neuroendocrine-immune interactions.14
Thus, testing and optimizing stress hormone (cortisol) levels and the stress response in your patients may support healthy hair growth.
Hair Loss Due to Fluctuating Estrogen Levels During Menopause and Pregnancy
Estrogen receptors are expressed locally in hair follicles, so estrogen directly affects hair growth. Estrogen also indirectly affects hair growth via its influence on androgen metabolism since androgens are the precursors for estrogens.8
The most powerful estrogen is estradiol, and research shows estradiol prolongs the anagen phase while decreasing the length of the telogen phase in human scalp hair. When estradiol levels decrease, the transition from anagen to telogen hastens, leading to increased hair loss.15 Two life events that offer insight into the effects of shifting estrogen levels on hair growth are pregnancy and menopause.6
Postpartum Hair Loss & Thinning (Telogen Gravidarum)
During pregnancy, estradiol levels are naturally higher and associated with increased hair diameter, increased hair growth, delayed teloptosis, reduced hair shedding, and a higher anagen/telogen ratio. Hair loss is expected postpartum due to the abrupt decrease in hormone levels. The naturally occurring hair loss after birth is known as postpartum telogen effluvium or telogen gravidarum.8,3
Moms who develop telogen gravidarum note that increased hair shedding begins two to four months after delivery and lasts 6 to 24 weeks. Sometimes, the increased hair shedding can persist for up to 15 months postpartum.8
Many hormonal changes occur during pregnancy, including increased levels of human chorionic gonadotropin, progesterone, prolactin, numerous growth factors, and cytokines, so other hormones may also contribute to the changes in hair growth in pregnant women. Menopause is a life stage characterized by estrogen depletion; thus, it provides more precise insight into the effects estrogens have on hair growth.8
Menopausal Hair Loss
During menopause, estrogen levels naturally decrease, promoting the miniaturization of the hair follicles in the scalp.1 This estrogen depletion is associated with female-pattern hair loss on the scalp and increased hair growth on the face (facial hirsutism).8 A quarter (25%) of all women are affected by female-pattern hair loss by the age of 50.1
In female pattern hair loss, the frontal hairline of women is often spared, most likely because it has a relatively higher level of aromatase. Aromatase is the enzyme that naturally converts androgens to estrogens. This phenomenon also demonstrates the protective role of estrogen on hair growth.6
When systemic estrogen levels abruptly decrease at menopause, it initiates a cascade of hormonal shifts leading to changes in hair growth in women. One significant change that can occur is a decrease in the sex hormone binding globulin (SHBG) level because estrogen stimulates the production of SHBG.8
SHBG is a blood protein that carries hormones through the blood to distribute them to cells. When a hormone is bound to SHBG, it is inactive. Hormones not bound to SHBG or other blood proteins are known as free hormones. Only the free, active hormones affect the function of cells and tissues throughout the body.
One of the benefits of saliva hormone testing is the direct measurement of the free hormone level. SHBG and other blood proteins are not in saliva, so only the free hormones diffuse into saliva.
The natural decrease in the SHBG level at menopause often causes a clinically significant boost in androgen activity since the free androgen levels, including testosterone and dihydrotestosterone (DHT), tend to increase. The secretion rate of androgens is typically maintained until the later stages of life in women, so an imbalance between estrogen and androgen levels often develops after menopause. The shift in the estrogen-to-testosterone ratio that begins at menopause may drive the decrease in scalp hair growth after menopause, even when the total estrogen and androgen levels are normal.8
It is interesting to note that when total blood levels of androgens are tested in menopausal and premenopausal women, the levels are similar, which is why it is so important to directly test the free hormone levels in saliva instead when there are signs of hyperandrogenism in menopausal women.8
While this exploration of the effects of estrogen on hair growth has primarily focused on women, estrogen replacement therapy has been tested as a treatment for hair loss in male patients, and it was associated with extensive hair regrowth when used in conjunction with other hair loss treatments.6
Changes in free progesterone levels throughout life can also significantly impact hair health.
Progesterone and Hair Loss
Research shows progesterone receptors are present in hair follicles, sebaceous glands, and keratinocytes; therefore, progesterone directly affects hair growth. Progesterone also indirectly supports healthy hair growth via its effects on other hormone levels.1
A healthy progesterone level reduces the excessive secretion of Luteinizing Hormone (LH) from the pituitary gland. LH acts on the reproductive organs to increase androgen production in men and women. As noted above, high free androgen levels can cause hair loss, so a healthy progesterone level supports robust hair growth by optimizing LH and androgen levels.8
At the level of the hair follicle, progesterone directly decreases the conversion of testosterone to dihydrotestosterone (DHT) by inhibiting the 5-alpha reductase enzyme.8 Therefore, low progesterone levels are associated with high free DHT levels within the hair follicles, which can cause excessive hair loss in men and women.1,8,16
Here are the results of a saliva hormone test panel depicting an elevated free DHT level in a female patient with hair loss:
Unfortunately, thus far, there are no clinical studies that have assessed the impact of the application of bioidentical progesterone to the scalp on hair quantity and quality in those with excessive hair loss.1
How to Stop Hormonal Hair Loss
To stop hormonal hair loss, one must determine what hormone, or hormones might be contributing to the hair loss. Saliva hormone testing is the best option for assessing steroid hormone levels because it directly measures the bioactive, free hormone levels. Free hormones are the hormones that are actively affecting cells and tissues throughout the body, including the hair follicles.
Once you assess salivary (free) hormone levels, you can recommend treatment options to optimize hormone levels and balance. One treatment option to consider when a patient’s salivary DHT level is either frankly elevated or high in comparison to their free testosterone or estrogen levels is a natural 5-alpha reductase inhibitor.
5-alpha reductase is the enzyme that converts testosterone to DHT. A natural 5-alpha reductase inhibitor is Saw Palmetto.17 You might also consider assessing and addressing the underlying cause(s) of the increased 5-alpha reductase activity in your patients. For example, insulin resistance is known to increase 5-alpha reductase activity; hence, improving insulin levels and blood glucose management may also reduce an elevated DHT level.18 The Adrenal Stress Index Panel includes tests that screen for insulin resistance.
Other Underlying Causes of Hair Loss
While abnormal steroid hormone levels can cause hair loss, there are many other underlying causes of excessive hair loss, including nutrient deficiencies, autoimmune activity, and exposure to toxic metals, such as thallium, arsenic, mercury, lead, and cadmium. Abnormal levels of non-steroid hormones, which include melatonin, thyroid hormones, IGF-1, and prolactin, may also contribute to hair loss.
If you are concerned about hair loss, now is the time to assess and address the underlying cause(s) since some medical conditions associated with hair loss require immediate medical treatment.
The Best Test Panels for Hair Loss
Measure salivary (free) steroid hormone levels by ordering a:
Also, consider screening for exposure to toxic metals with a Toxic Metals and Elements Panel.
At Larrea Naturopathic Medicine, we can support our patients experiencing hair loss by identifying underlying hormonal imbalances and stress-related contributors. Salivary hormone testing offers a non-invasive, accurate way to assess key hormones like cortisol, DHEA, estrogen, progesterone, and testosterone. With this information, you can create personalized, root-cause treatment strategies that help restore hormonal balance—and confidence.
If you would like to acquire testing, please give our clinic a call at (520) 222-6208. We’re here to help.
References:
Gasser S, Heidemeyer K, von Wolff M, Stute P. Impact of progesterone on skin and hair in menopause – a comprehensive review. Climacteric. 2021;24(3):229-235. doi:10.1080/13697137.2020.1838476
Piraccini BM, Alessandrini A. Androgenetic alopecia. G Ital Dermatol Venereol. 2014;149(1):15-24.
Hasan R, Juma H, Eid FA, et al. Effects of Hormones and Endocrine Disorders on Hair Growth. Cureus. 2022;14(12):e32726. doi:10.7759/cureus.32726
Liu LP, Li MH, Zheng YW. Hair Follicles as a Critical Model for Monitoring the Circadian Clock. Int J Mol Sci. 2023;24(3):2407. doi:10.3390/ijms24032407
Do you have hair loss or hair shedding? American Academy of Dermatology. Accessed July 28, 2023. https://www.aad.org/public/diseases/hair-loss/insider/shedding.
Natarelli N, Gahoonia N, Sivamani RK. Integrative and Mechanistic Approach to the Hair Growth Cycle and Hair Loss. J Clin Med. 2023;12(3):893. doi:10.3390/jcm12030893
Saleh D, Nassereddin A, Cook C. Anagen Effluvium. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482293/
Grymowicz M, Rudnicka E, Podfigurna A, et al. Hormonal Effects on Hair Follicles. Int J Mol Sci. 2020;21(15):5342. doi:10.3390/ijms21155342
Rebora A, Guarrera M. Teloptosis and kenogen: two new concepts in human trichology. Arch Dermatol. 2004;140(5):619-620. doi:10.1001/archderm.140.5.619
10.Martel JL, Miao JH, Badri T. Anatomy, Hair Follicle. [Updated 2022 Oct 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470321/
11.Guarrera M, Rebora A. The Higher Number and Longer Duration of Kenogen Hairs Are the Main Cause of the Hair Rarefaction in Androgenetic Alopecia. Skin Appendage Disord. 2019;5(3):152-154. doi:10.1159/000493587
12.Kesika P, Sivamaruthi BS, Thangaleela S, et al. Role and Mechanisms of Phytochemicals in Hair Growth and Health. Pharmaceuticals (Basel). 2023;16(2):206. doi:10.3390/ph16020206
13.Kraemer WJ, Ratamess NA, Hymer WC, et al. Growth Hormone(s), Testosterone, Insulin-Like Growth Factors, and Cortisol: Roles and Integration for Cellular Development and Growth With Exercise. Front Endocrinol (Lausanne). 2020;11:33. doi:10.3389/fendo.2020.00033
14.Wang Q, Wu H, Zhou J, et al. Involvement of the central hypothalamic-pituitary-adrenal axis in hair growth and melanogenesis among different mouse strains. PLoS One. 2018;13(10):e0202955. doi:10.1371/journal.pone.0202955
15.Lephart ED. Human scalp hair: Modulation by various factors and hormones do estrogens inhibit or stimulate-A perplexing perspective. J Cosmet Dermatol. 2019;18(6):1860-1865. doi:10.1111/jocd.12888
16.Thom E. Stress and the Hair Growth Cycle: Cortisol-Induced Hair Growth Disruption. J Drugs Dermatol. 2016;15(8):1001-1004.
17.Devjani S, Ezemma O, Kelley KJ, et al. Androgenetic Alopecia: Therapy Update. Drugs. 2023;83(8):701-715. doi:10.1007/s40265-023-01880-x
18.Sadgrove NJ. The new paradigm for androgenetic alopecia and plant-based folk remedies: 5α-reductase inhibition, reversal of secondary microinflammation and improving insulin resistance. J Ethnopharmacol. 2018;227:206-236. doi:10.1016/j.jep.2018.09.009
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