14 Things to Know When You’re Starting Compound GLP-1s

Because of high demand and other issues, the FDA temporarily allowed special pharmacies to make weight loss drugs like semaglutide (Ozempic, Rybelsus, Wegovy) and tirzepatide (Mounjaro, Zepbound). Now that the shortage is over, compounded GLP-1s aren’t FDA-approved or backed by the same safety checks. Some pharmacies add extra ingredients like B12 to get around this ruling, but that doesn’t necessarily make them safer. Consider these tips if you’re about to start using one.

You won’t get in trouble for telling your doctor you’re using a compounded GLP-1. In fact, it’s the safest thing you can do. Your provider can check for side effects and go over dosing. They can also go over the pros and cons of switching to an approved version, especially since the cost has come down and access has improved.

Compounded GLP-1s aren’t made the same way as FDA-approved meds. That means the quality, strength, and ingredients can vary. The FDA has gotten reports of people giving themselves the wrong dose from multiuse vials. Some needed medical care or even went to the hospital. Side effects included nausea, vomiting, belly pain, and fainting, along with headaches, dehydration, pancreatitis, and gallstones. If you’re using these meds, it’s extra important to measure carefully and watch for signs that something’s not right.

GLP-1 side effects like nausea or fatigue can show up fast, sometimes within 24 hours. So it’s a good idea to start on a Friday night or whenever you have some downtime. That way, you can rest and see how your body responds. 

Look for the drug name (like semaglutide), strength (how many mg per mL, for example), volume (how much liquid per dose), and beyond use date (BUD). The BUD tells you how long the drug is safe to use. Most GLP-1s need to stay in the fridge. If you’re taking it out each week, make sure it’s kept cold and clean in between. If you’re confused, ask your pharmacist or check out FDA alerts to learn about common label mix-ups.

Dosage is the amount of the drug (like 0.25 mg). Concentration tells you how much is in each mL (like 5 mg/mL). Volume is how much liquid you inject. Units are the marks on your syringe, and they’re not the same for every syringe. If your math is off, your dose could be way too high. Ask a pharmacist or use a peptide dosing calculator to double-check.

If you’re drawing from a vial, use the right kind of syringe. Follow the math exactly. Accidentally injecting 10 or 20 times your dose is a real risk with compounded meds. That’s the kind of error that’s landed some people in the hospital. Always triple-check your math and ask for help if you’re unsure.

Most people say the injection feels like a light rubber band snap. But if you’re using a vial and needle instead of an FDA-approved auto-injection pen, the anxiety can be real. Watch a how-to video or practice with a nurse if you can.

You can inject GLP-1s into your thigh, upper arm, belly, or your butt if you can reach it. There’s no best place. Rotate injection sites to avoid skin irritation. Not sure how to inject subcutaneously, or under the skin? We’ve got a how-to explainer here.

Common issues include nausea, fatigue, and constipation. Call your doctor if you can’t drink or eat for more than 24 hours, have six or more bowel movements in one day, or feel unusually tired. You should also call if your mouth is dry or your skin seems loose. Those are signs of dehydration or other serious issues. Compounded drugs might also trigger allergic reactions like hives, rashes, or breathing problems. If you feel dizzy, weak, or can’t keep down fluids, go to the emergency room right away.

Most people feel less hungry within 24 hours. But weight loss takes longer. A safe pace is about 1-2 pounds per week. Losing more than that? Let your doctor know. It could mean your dose is too high.

Ideally, your doctor will up the dose every month as your body adjusts. If nausea hits hard, they may lower it, keep you at the current dose for a bit longer, or prescribe anti-nausea meds. Talk to your doctor if you’re losing weight too fast or struggling to eat. They may need to take you down a notch.

If you’re less than four days late, take your shot and continue as usual. If it’s been longer, skip the dose and go back to your regular schedule. Don’t give yourself two shots at once. If you’re still working your way up to a full dose, missing more than one shot may set you back. Ask your doctor what to do if you’ve gone two weeks or more without an injection.

GLP-1s may be a long-term or even lifelong medication. Most people regain weight when they stop. If you’re worried about staying on injections, ask your doctor about GLP-1 drugs you take by mouth or other options like bariatric surgery.