The short version

You don’t have to choose between the medication working and keeping your hair — but keeping your hair while on a GLP-1 takes deliberate effort, because the drug suppresses exactly the thing your hair feeds on: food. The protocol is unglamorous. Hit your protein. Eat enough, period. Get the right labs checked. Don’t megadose vitamins. Treat the hair you have gently while it’s fragile. And have the pacing conversation with your prescriber, not your stylist.

Part of our GLP-1 & Your Hair series. Part 1 explains why this happens. Already shedding? Skip to Part 3, the recovery protocol. Educational only — not medical advice.

1. Protein first, at every meal

Hair is protein. When intake crashes, your body stops building it. This is the single biggest lever you control.

In 2025, four major medical bodies — the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society — issued joint nutrition guidance for GLP-1 patients. Their protein range during active weight loss: 1.2–1.6 grams per kilogram of body weight per day, well above the standard 0.8 g/kg RDA. For many adults that works out to roughly 80–120 grams a day. (The calculation uses adjusted body weight, which is exactly why a dietitian should set your number, not a blog.)

How people actually hit it on a suppressed appetite:

• Lead every meal with 20–30 g of protein — eggs, Greek yogurt, chicken, fish, tofu, beans — before anything else on the plate.
• Eat smaller, more often. Three big meals are unrealistic on these drugs; planned protein snacks are not cheating, they’re the strategy.
• Keep a protein shake (20 g or more) in reserve for the days you cannot face food. Low-intake days are when hair pays.

One honest caveat: that protein target exists primarily to protect your muscle — lean mass is a quarter to two-fifths of what people lose on these medications. Protecting your hair is a likely benefit of eating enough protein, not a trial-proven guarantee. Anyone who promises you a protein number that “prevents hair loss” is ahead of the evidence.

2. Pair it with resistance training

The same joint guidance is blunt: protein alone doesn’t preserve lean mass without resistance training. Two to three strength sessions a week is the consistent recommendation. Muscle is where the protein goes; training is the signal that tells your body to keep it. This is a hair post, but the physiology is one system — patients who protect their muscle and eat adequately are the ones whose bodies aren’t in emergency triage mode, shedding included.

3. Get labs checked — find real deficiencies, don’t guess

If you do one medical thing from this post, make it this: ask your prescriber whether your labs should be checked, especially if shedding starts or drags on. The panel clinicians ask for when hair is shedding:

• Ferritin and iron studies
• Vitamin D
• Vitamin B12
• Zinc
• TSH (thyroid) and a CBC

Low ferritin is the one linked to shedding most often. A note of caution on numbers you’ll see online: posts claiming your ferritin must be “70 to 100 for hair growth” are stating a target the literature doesn’t agree on. Your clinician interprets your results. That’s the job.

4. The supplement trap — read this before buying anything

The hair-supplement aisle is where good intentions go to overspend. Three facts worth knowing:

• Biotin has no evidence behind it for hair growth in people who aren’t deficient, and deficiency is rare. Worse: high-dose biotin distorts lab results — thyroid tests, vitamin D, even the troponin test used to detect heart attacks. The FDA has issued a warning about exactly this. If you take it, tell your clinician and your lab, and expect to be told to stop it 48–72 hours before blood draws.
• Too much of a “hair vitamin” causes hair loss. Excess vitamin A, selenium, vitamin E, and chronic high-dose zinc are all associated with shedding. More is not better. More is sometimes the problem.
• Supplements are for confirmed deficiencies. Iron, zinc, and vitamin D help when a lab says you’re low and a clinician sets the dose. Taken blind, at best they do nothing.

If a product promises to “block GLP-1 hair loss,” close the tab.

5. Slow is protective — but that’s your prescriber’s call

No study has established a “safe” rate of weight loss for hair, and we’d rather tell you that than invent one. What the evidence does support: shedding tracks rapid, large losses, and it eases when weight stabilizes. So the pace conversation is worth having — how fast you’re escalating dose, how fast the weight is coming off, whether a dietitian should be involved.

Have that conversation with your prescriber. Do not stop, skip, pause, or stretch doses on your own to save your hair, and don’t take that advice from anyone who isn’t prescribing for you.

6. In the salon: protect the hair you have

While you’re losing weight, your hair is under nutritional stress and breaks more easily. Breakage isn’t shedding — it doesn’t change what comes out of the follicle — but it’s the difference between thinning that shows and thinning that doesn’t. Our standing advice for clients on GLP-1s:

• Go easy on chemical load. Postpone high-lift bleach and chemical straightening during active loss phases; choose gentler color — dimensional color, glosses, root work — that doesn’t push fragile hair.
• Turn the heat down. Lower dryer and iron settings, heat protectant every time.
• Nothing tight. Ponytails, weaves, and extensions that pull can turn temporary shedding into traction damage, which can become permanent. If a style hurts, it’s too tight — tell us and we’ll loosen it.
• Defer new extension installs while you’re actively shedding. Added weight on fragile, shedding hair is a bad trade. We’ll assess honestly and tell you when your hair can carry them again.
• Detangle gently, condition generously. Fragile hair snaps at the comb, not the root.

Tell your stylist you’re on a GLP-1. It changes what we recommend, the same way telling us you’re pregnant or post-surgery would — it’s context we work better with, not gossip.

Your prescriber checklist

Bring this list. Five minutes, real answers:

1. Am I losing at a pace we expected? Should dose escalation slow down?
2. Should I see a dietitian to set my protein target?
3. Are baseline or follow-up labs worth running — ferritin, vitamin D, B12, zinc, thyroid?
4. Here’s everything I take, including gummies and “hair vitamins” — any problems with labs or interactions?
5. If I start shedding heavily, when do you want to hear about it?

FAQ

How much protein do I need on a GLP-1 to protect my hair?

The 2025 joint medical guidance for GLP-1 patients recommends 1.2–1.6 g/kg/day during active weight loss — roughly 80–120 g/day for many adults — mainly to preserve muscle. Have a dietitian set your personal number; the math uses adjusted body weight.

Should I take biotin or a hair gummy, just in case?

No strong evidence supports it unless you’re deficient, and high-dose biotin can corrupt lab results — including thyroid and cardiac tests. It’s the one supplement we’d actively steer you away from starting blind.

Can my stylist do anything to stop the shedding?

No — shedding is decided at the follicle, months before the hair lets go. What we control is breakage, styling stress, and how full your hair looks while you ride it out. Anyone offering a treatment that “stops GLP-1 shedding” is overpromising.

Is it better to lose weight slower?

Shedding tracks fast, large losses, and eases when weight stabilizes — but there’s no proven pounds-per-week threshold for hair. Pace is a medical decision to make with your prescriber.

Get a hair plan that matches your medication plan

Deniece Pittman, our Master Stylist and hair loss specialist, builds hair-care plans for clients on GLP-1s — what to pause, what to switch, what your hair can handle right now.

Book a consultation online or call 614.547.2566. PLEIJ Salon + Spa, 8930 Lyra Dr, Columbus, OH 43240.

See our hair services.

Sources: Joint advisory on nutrition in GLP-1 therapy, American College of Lifestyle Medicine / American Society for Nutrition / Obesity Medicine Association / The Obesity Society (2025); FDA safety communication on biotin interference with lab tests; American Academy of Dermatology, guidance on hair damage from weaves and extensions; Medscape coverage of EADV 2025 GLP-1 hair loss research.