Is Hair Thinning Associated With Semaglutide?

Clinical trials evaluating semaglutide for weight management have reported hair thinning in a small proportion of participants. In large randomized studies, approximately 3% of individuals receiving semaglutide reported hair loss, compared with approximately 1% in placebo groups.

Investigators have noted that this pattern is consistent with telogen effluvium, a temporary and reversible hair shedding condition that can occur following significant weight loss, metabolic stress, illness, or dietary changes. Similar patterns of hair shedding have been documented following bariatric surgery and non-pharmacologic weight loss interventions, supporting the interpretation that the observed hair thinning is related to systemic physiological stress rather than direct follicular toxicity.

Hair Thinning Observed With Tirzepatide

Clinical trials of tirzepatide have reported slightly higher rates of hair thinning at higher doses, with approximately 5–6% of participants affected in some studies. Tirzepatide is associated with greater average weight loss compared with semaglutide, which may contribute to this difference.

As with semaglutide, available data do not suggest that tirzepatide directly damages hair follicles. The timing, diffuse scalp distribution, and reversibility of shedding are consistent with stress-related changes in hair cycling rather than medication-induced alopecia.

Why Hair Shedding May Occur During Weight Loss

Hair growth occurs in cyclical phases, with the majority of follicles actively growing at any given time. Physiological stressors—including rapid weight loss, caloric restriction, and metabolic shifts—can prompt a greater proportion of follicles to enter the resting (telogen) phase simultaneously. This shift results in diffuse hair shedding across the scalp without scarring or permanent follicular injury.

During GLP-1–associated weight loss, several factors may contribute to this process, including sustained caloric deficits, reduced protein intake due to appetite suppression, changes in micronutrient intake, and metabolic adaptation as body weight decreases. Hair shedding related to these mechanisms typically becomes noticeable two to four months after the triggering event.

Is This Type of Hair Thinning Reversible?

In most cases, yes. Telogen effluvium is generally considered a temporary condition. Dermatologic literature describes a typical recovery pattern in which shedding may persist for several months before gradual regrowth occurs. New hair growth often begins within three to six months, with progressive improvement in density over six to twelve months.

Recovery timelines vary depending on factors such as age, baseline hair density, nutritional status, and overall health. Importantly, current evidence does not suggest permanent follicular damage associated with semaglutide or tirzepatide when used as prescribed.

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Support With Key Nutrients

During periods of weight loss, nutritional intake may change due to reduced appetite and lower caloric consumption. Certain micronutrients play established roles in normal hair follicle function and hair growth cycles, and insufficient intake may contribute to hair shedding during periods of metabolic stress.

Licensed healthcare providers may consider evaluating nutritional status when hair thinning is reported. Nutrients commonly discussed in this context include:

• Iron: Iron supports oxygen delivery to hair follicles and is essential for normal hair growth. Low iron stores, often assessed using ferritin levels, have been associated with increased hair shedding. Evaluation and supplementation should only be pursued when clinically indicated and under medical supervision.
• Vitamin D: Vitamin D is involved in hair follicle cycling and immune regulation. Deficiency is relatively common and has been observed in individuals experiencing diffuse hair thinning. Providers may assess vitamin D status as part of a broader clinical evaluation when appropriate.
• Biotin: Biotin contributes to keratin structure within hair, skin, and nails. While true biotin deficiency is uncommon, supplementation may be considered in select cases based on dietary intake and clinical context.
• Zinc: Zinc supports hair tissue growth and repair and plays a role in follicular function. Inadequate zinc intake has been linked to hair shedding, particularly during periods of restricted nutrition or rapid weight loss.
• Omega-3 Fatty Acids: Omega-3 fatty acids may support scalp health and inflammatory balance. Although evidence specific to hair regrowth is still evolving, these nutrients are commonly included in discussions of general hair and skin wellness.

Any supplementation should be individualized and guided by a licensed healthcare provider to avoid unnecessary or excessive intake. Addressing overall nutrition, including adequate protein and micronutrient intake, may support the body’s adaptation to weight changes and normal hair growth over time.

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General Supportive Considerations

Although no intervention can guarantee prevention of hair shedding during weight loss, clinicians often discuss general supportive strategies such as maintaining adequate dietary protein intake, avoiding severe or prolonged caloric restriction, monitoring iron, vitamin D, and zinc status when clinically indicated, and using gentle hair care practices to minimize mechanical stress.

All dietary or supplement changes should be discussed with a licensed healthcare provider.

Clinical Perspective

Current evidence suggests that hair thinning reported during GLP-1 therapy reflects the body’s response to metabolic and nutritional changes rather than medication-induced follicular damage. Available data do not indicate permanent hair loss associated with semaglutide or tirzepatide when used under appropriate medical supervision.

Ongoing research continues to monitor dermatologic outcomes as GLP-1 therapies are used more broadly in clinical practice.
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References

• Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine. 2021;384(11):989-1002. doi:10.1056/NEJMoa2032183.
• U.S. Food and Drug Administration. Wegovy (semaglutide) injection, for subcutaneous use: highlights of prescribing information. Updated August 2025.
• Hughes EC, Saleem MD. Telogen effluvium. StatPearls. Updated May 2024.
• Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine. 2022;387(3):205-216. doi:10.1056/NEJMoa2206038.
• Malkud S. Telogen effluvium: a review. Journal of Clinical and Diagnostic Research. 2015;9(9):WE01-WE03. doi:10.7860/JCDR/2015/15219.6492.
• Leite AC, Leite Jr AC. Telogen effluvium and metabolic stress in modern weight loss interventions: a narrative clinical review. Brazilian Journal of Hair Health. 2025;3(1).
• Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The role of vitamins and minerals in hair loss: a review. Dermatology and Therapy. 2019;9(1):51-70.

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