Quick answer: hair loss was reported more often than with placebo in trials of both medicines: about 3% vs 1% on the Wegovy label and up to about 5% vs 1% on the Zepbound label, more often in women. It's usually telogen effluvium, temporary shedding triggered by rapid weight loss and eating less, which typically starts 2 to 4 months after the trigger and grows back over about 6 months. Enough protein and calories, iron, and avoiding crash dieting are the main levers. Tell your doctor if it's heavy, patchy or lasts more than 6 months.
Educational only, not medical advice. This article explains general information and quotes official labels where noted. It doesn't recommend any dose or change to your treatment. Follow your prescriber's instructions and the product label.
This post is part of our GLP-1 side effects guide.
Is it the drug or the weight loss?
The evidence points mostly to the weight loss itself. Hair shedding is well known after bariatric surgery and very-low-calorie diets, where no GLP-1 is involved. In the Zepbound and Wegovy trials, people who lost more weight were more likely to report hair loss. Whether GLP-1s have any direct effect on hair isn't established.
What is telogen effluvium?
Normally about 10% of hair follicles are in the resting (telogen) phase. A shock to the body, such as rapid weight loss, illness, surgery or a big drop in calories or protein, pushes more follicles into rest at once. About 2 to 4 months later they shed together. The American Academy of Dermatology notes this shedding usually stops by itself and hair regains its fullness within 6 to 9 months.
Can you stop GLP-1 hair loss?
You can't always prevent it, but you can lower the odds and support regrowth:
- Get enough protein. GLP-1s cut appetite so much that protein often drops. Many obesity and nutrition guidelines suggest around 1.0 to 1.5 g of protein per kg of ideal or reference body weight a day during weight loss, but your clinician or a dietitian should set your target. See what to eat on a GLP-1.
- Avoid very low calorie days when appetite is suppressed.
- Ask about labs. Iron (ferritin), thyroid, vitamin D, zinc and B12 deficiencies can also cause shedding.
- Be gentle with hair. Tight styles and harsh treatments add breakage.
- Talk to a dermatologist about treatments such as minoxidil if shedding is heavy or doesn't recover.
How long does it last?
Shedding from telogen effluvium usually runs for a few months and then slows. Regrowth takes months because hair grows about half an inch a month. Shedding that lasts beyond 6 months, comes in patches, or comes with scalp redness or scaling is not typical telogen effluvium and should be checked.
Should you stop the medication?
That's a decision for your prescriber. Because shedding is usually temporary, many people continue treatment while working on nutrition. Follow your prescriber.
Tracking it in Caliper
Log shedding in a check-in, use meal logging to keep an eye on protein, and look at the weight chart with dose overlay. Seeing hair changes next to how fast your weight dropped helps your provider judge the likely cause.
FAQ
Does Wegovy cause hair loss?
Hair loss was reported in about 3% of people on Wegovy vs 1% on placebo in trials. It's usually temporary shedding linked to rapid weight loss.
Does Zepbound cause hair loss?
The Zepbound label reports hair loss in up to about 5% of people vs 1% on placebo, more often in women. It's usually temporary shedding linked to weight loss.
Will my hair grow back?
Telogen effluvium usually stops on its own and hair regains its fullness within 6 to 9 months. See a doctor if it lasts longer or is patchy.
Can protein prevent GLP-1 hair loss?
Low protein and calories make shedding more likely. Getting enough protein, with a target set by your clinician or dietitian, is one of the main things you can do.
Should I stop Wegovy or Zepbound because of hair loss?
Talk to your prescriber. Because the shedding is usually temporary, many people continue while improving nutrition.
Sources
- Novo Nordisk, Wegovy prescribing information
- Eli Lilly, Zepbound prescribing information
- American Academy of Dermatology, Do you have hair shedding or hair loss?
- Jastreboff AM et al., SURMOUNT-1, NEJM 2022
Keep the whole picture in one place
Caliper is a GLP-1 and peptide tracker. It logs doses, check-ins, meals and water, and overlays dose steps on your weight chart. It never recommends or calculates a dose.
For adults 18+.
Medical disclaimer: This article is for general educational purposes only and is not medical advice. It does not recommend any dose, compound, product, supplier or protocol. Always follow your prescriber's instructions and the product label, and talk to a pharmacist or healthcare provider about any question regarding your medication.