Extra hair in the shower drain, a red patch two days after you used the pen, a face that looks different in the mirror. You started a GLP-1 medicine and now something on your skin, hair or nails has changed.
This guide helps you match what you see with what is known, shows which guide fits your situation, and lists the few signs that mean you should not wait.
Quick answer: Yes, several skin, hair and injection site changes are recognized effects of this class of medicines. Most are mild and temporary. Hair shedding and injection site reactions are the two with numbers on the FDA labels. Face changes, loose skin, dry skin, acne and brittle nails are linked mostly to fast weight loss and eating less, according to dermatologists. A few signs need emergency or same-day care, listed below. Anything about the medicine itself is a decision for the prescriber who prescribed it.
Which GLP-1 side effect on your skin, hair or nails are you seeing?
| What you notice | What it often is | Where to read |
|---|---|---|
| Hair coming out in the shower or on the brush | Shedding after fast weight loss (telogen effluvium) | Hair loss on GLP-1 medicines and Will it grow back? The timeline |
| A red, itchy, bruised or lumpy spot where you inject | Injection site reaction | Injection site reactions |
| Not sure where to inject next | Site rotation | Injection site rotation |
| A rash, hives or itching away from the injection spot | Allergic-type or other rash | Rash on GLP-1 medicines |
| A thinner, older or more hollow face | Loss of facial volume with weight loss | Ozempic face |
| Brittle or slow-growing nails | Nail changes after weight loss | Brittle nails on GLP-1 medicines |
| Skin that burns or hurts to touch, no rash | Skin sensitivity | Skin sensitivity on GLP-1 medicines |
Which medicines this covers
Ozempic and Wegovy contain semaglutide. Mounjaro and Zepbound contain tirzepatide. They work in similar ways and share most of these effects, so the guides cover them together instead of one page per brand. Brand names appear only to say which medicine is meant.
Hair
Hair shedding is the effect people ask about most. The Wegovy label reports hair loss in 3.3% of people on the drug in its weight-loss trials versus 1% on placebo. The Zepbound label reports 4% to 5% versus 1%. A 2026 meta-analysis found hair loss about three times as likely as on placebo, with an overall rate of 3.9%. A 2025 joint advisory from four US medical and nutrition societies puts the drop in calorie intake on these medicines at 16% to 39%, which is part of why nutrition comes up so often.
Most of it is telogen effluvium: hairs pushed into rest by fast weight loss and much less food, which let go a few months later. The evidence is mostly observational, and cause has not been proven. Read hair loss on GLP-1 medicines for the checks and what to do, and the regrowth timeline for what the months ahead look like. The nutrition angle is covered in GLP-1 hair loss supplements.
Injection sites
Reactions where you inject are common and mostly mild. The labels report them in 0.2% of people on Ozempic, 1.4% on Wegovy (1% on placebo), 3.2% on Mounjaro (0.4% on placebo) and 6% to 8% on Zepbound (2% on placebo). Those come from different trials, so they are not a ranking. A 2026 review found skin and injection site reactions make up a large share of reported GLP-1 side effects, and that most are mild to moderate.
The Medication Guides say to change the injection site with each injection. Start with injection site reactions for what is normal and what is not, and injection site rotation for a diagram and a simple pattern.
Face, loose skin, dry skin and acne
The American Academy of Dermatology (AAD) lists what patients report: less plumpness in the face, sagging skin, wrinkles and a crepe-like texture, dry skin from hormone changes and from eating and drinking less, loose skin that folds on itself and can cause rashes where skin touches skin, and acne breakouts. Dermatologists say the face changes are partly from rapid weight loss, and that these medicines also affect collagen and muscle along with fat. More in Ozempic face.
Skin care basics from the AAD:
- A gentle cleanser, and a moisturizer with ceramides and antioxidants on your whole body, applied while the skin is damp.
- Retinoids can help with signs of aging but may irritate and flake dry skin.
- Broad-spectrum, water-resistant sunscreen, SPF 30 or higher.
- Plenty of fluids, and a humidifier if the air is dry.
- Keep skin folds clean and dry. Treat acne gently and do not pick.
Fillers, fat transfer, lasers and platelet-rich plasma are procedures to discuss with a board-certified dermatologist, not something this site recommends. Talk to a doctor before changing your routine, especially in pregnancy, while breastfeeding, on other medicines, or with kidney or liver disease. Guides on loose skin, wrinkles and dry skin are in preparation.
Rashes and hives
The Zepbound label says most hypersensitivity reactions in its trials were skin reactions such as rash and itching. The Ozempic and Wegovy labels list rash and hives among reports after approval. Most skin reactions are not emergencies, but a few signs are. On brown and Black skin a rash can look darker brown, purple or gray rather than red, so go by warmth, swelling and texture too. Start with rash on GLP-1 medicines, our skin rash guide and the rash checker.
Nails and skin sensitivity
The AAD lists slower nail growth and brittle nails after significant weight loss. See brittle nails on GLP-1 medicines and the general guide to brittle and splitting nails.
Some people describe skin that burns or hurts to touch with no visible rash. There is nothing to photograph, so skin sensitivity on GLP-1 medicines helps you prepare for the conversation with your doctor instead.
When a GLP-1 side effect is urgent
- Emergency (call 911 or go to the ER): swelling of the face, lips, tongue or throat, trouble breathing or swallowing, fainting or feeling dizzy, a very rapid heartbeat, or a severe rash or itching. The Medication Guides list these signs and say to get medical help right away. Tell the emergency team which medicine you use.
- Same-day doctor: redness at an injection site that keeps spreading, hot, swollen, painful skin, pus, a fever, or a rash with fever or blisters.
- Soon: anything that is not improving with time or that worries you.
What to do next
- Write down when the change started compared with when you began the medicine.
- Take clear photos in good light.
- Tell the prescriber. The person who prescribed the medicine decides about the medicine. Nobody on this site does.
- See a board-certified dermatologist if it is stubborn, as the AAD advises.
Most people start with the two guides for the most common worries: hair loss and injection site reactions.
Frequently asked questions
What are the skin side effects of Ozempic, Wegovy, Mounjaro and Zepbound?+
People report irritation where they inject, thinning hair, dry skin, acne, excessive sweating, brittle nails and, after a lot of weight loss, a thinner-looking face and loose skin. Most are mild. The American Academy of Dermatology links many of them to fast weight loss and eating and drinking less.
Does Ozempic cause hair loss?+
It can be linked to hair shedding, mostly the temporary kind that follows fast weight loss. The Wegovy label reports hair loss in 3.3% of people on the drug versus 1% on placebo, and the Zepbound label reports 4% to 5% versus 1%. See the full hair loss guide for what to do.
Is an injection site reaction normal?+
A mild red, itchy, sore or bruised spot is a commonly reported reaction and tends to fade. Spreading redness, heat, swelling, pus or a fever needs a doctor the same day, and swelling of the face, lips or tongue needs emergency care.
Why do I look older on a GLP-1 medicine?+
The American Academy of Dermatology says patients notice less plumpness in the face, sagging skin, wrinkles and a crepe-like texture, partly from rapid weight loss, and that these medicines also affect collagen and muscle along with fat. If it bothers you, a board-certified dermatologist can talk through options.
Can GLP-1 medicines cause a rash?+
Yes. The Zepbound label says most hypersensitivity reactions in its trials were skin reactions such as rash and itching, and the Ozempic and Wegovy labels list rash and hives among reports after approval. A rash with swelling of the lips or face, or trouble breathing, is an emergency.
Do GLP-1 side effects on the skin go away?+
Many are mild and temporary, and hair shedding of the usual kind tends to recover over months. It depends on what you have, so ask the prescriber and, if it persists, a board-certified dermatologist.
Sources
- Novo Nordisk. Wegovy (semaglutide) injection prescribing information and Medication Guide. DailyMed, label revised June 2026. DailyMed
- Eli Lilly and Company. Zepbound (tirzepatide) prescribing information and Medication Guide. DailyMed, label revised September 2026. DailyMed
- Novo Nordisk. Ozempic (semaglutide) injection prescribing information and Medication Guide. DailyMed, label revised June 2026. DailyMed
- Eli Lilly and Company. Mounjaro (tirzepatide) prescribing information and Medication Guide. DailyMed, label revised September 2026. DailyMed
- American Academy of Dermatology. How can GLP-1 drugs affect my skin, hair, and nails? Updated February 2026. aad.org
- Elgindi D, Petronic-Rosic V. Glucagon-like peptide-1 receptor agonist-associated injection site and dermatologic reactions. Clinics in Dermatology. 2026. PubMed 42692277
- Cheng PL, Chang HC. Glucagon-like peptide-1 receptor agonists and hair loss: a systematic review and meta-analysis. Diabetes Research and Clinical Practice. 2026. PubMed 42155605
- Piraccini BM, Vañó-Galván S, Blume-Peytavi U, et al. Hair loss in patients on glucagon-like peptide 1 receptor agonists: understanding risks and managing outcomes. Dermatology and Therapy. 2026. PubMed 42249225
- Mozaffarian D, Agarwal M, Aggarwal M, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. American Journal of Clinical Nutrition. 2025. PubMed 40450457
This article is for general education and is not medical advice. It does not replace a consultation with a qualified clinician. If a symptom worries you, see a doctor.