Weight loss peptides are available through a prescription from a licensed healthcare provider, filled at either a standard pharmacy or, in limited cases, a compounding pharmacy. The two FDA-approved peptide-based options are Wegovy (semaglutide) and Zepbound (tirzepatide), both of which require a medical evaluation and a prescription. There is no legal, safe way to buy these medications without one.
FDA-Approved Peptide Medications
The peptides currently approved for chronic weight management work by mimicking gut hormones that regulate appetite and food intake. Wegovy, made by Novo Nordisk, targets one of these hormones (GLP-1). Zepbound, made by Eli Lilly, targets two (GLP-1 and GIP), which appears to give it a slight edge. A head-to-head trial published in the New England Journal of Medicine found that people on tirzepatide (Zepbound’s active ingredient) lost an average of 20.2% of their body weight over 72 weeks, compared to 13.7% for those on semaglutide (Wegovy’s active ingredient).
Both are once-weekly injections you give yourself at home using a prefilled pen. There is also an oral form of semaglutide (Rybelsus), though it was developed for type 2 diabetes rather than weight loss specifically. Oral peptide absorption is inherently poor because stomach acid and the intestinal lining break down most of the compound before it reaches the bloodstream, so injectable versions remain the standard for weight management.
Getting a Prescription
You have several paths to a prescription. Your primary care doctor can prescribe these medications, as can endocrinologists and obesity medicine specialists. A growing number of telehealth platforms and dedicated weight loss clinics also offer consultations, often entirely online. The typical process starts with a health history review, a discussion of your goals, and sometimes bloodwork to check for metabolic issues like insulin resistance or thyroid dysfunction.
To qualify, most prescribing guidelines require a BMI of 30 or higher, or a BMI of 27 or higher if you also have a weight-related condition such as type 2 diabetes, high blood pressure, high cholesterol, or obstructive sleep apnea. These are the same thresholds insurance companies generally use when deciding whether to cover the medication.
What It Costs
Cost is the biggest barrier for most people. Without insurance, both Wegovy and Zepbound are available through manufacturer direct-purchase programs at $499 per month, with Zepbound’s lowest starter dose priced at $349 per month. If your insurance covers obesity medications, your copay could be significantly less, but coverage varies widely by plan. Medicare currently does not cover obesity medications at all, which leaves many older adults paying entirely out of pocket.
If your insurance denies coverage, it’s worth asking your provider to submit a prior authorization. Documenting weight-related health conditions can sometimes change the outcome. Both Novo Nordisk and Eli Lilly also run savings programs for commercially insured patients.
Compounding Pharmacies: A Shifting Landscape
During recent shortages of semaglutide and tirzepatide, compounding pharmacies stepped in to produce custom versions of these drugs at lower prices. Compounded medications are not FDA-approved, meaning they haven’t gone through the standard review process for safety, effectiveness, or quality. They were legally permitted to make copies of these drugs only because the brand-name versions were on the FDA’s official drug shortage list.
That window is closing. As supply has stabilized, the FDA has been tightening enforcement. As of early 2025, the enforcement discretion period for compounded semaglutide under standard pharmacy compounding rules (section 503A) has ended. For larger outsourcing facilities (section 503B), the FDA extended a narrow grace period into mid-2025, but the direction is clear: once a drug is no longer in shortage, compounding pharmacies generally cannot produce copies of it.
The FDA has also flagged specific safety concerns. Some compounders used salt forms of semaglutide that the agency says may not have the same chemical properties as the approved drug. Two other peptides sometimes marketed for weight loss, retatrutide and cagrilintide, cannot legally be used in compounding at all under federal law.
Why “Research Chemical” Peptides Are Risky
Websites selling peptides labeled “for research purposes only” are a different category entirely. These products are not manufactured under pharmaceutical-grade controls, and there’s no guarantee of purity, dose accuracy, or sterility. You have no way to verify what’s actually in the vial. Injecting an impure or mislabeled compound can cause infections, allergic reactions, or unpredictable side effects. The FDA has specifically warned consumers against using unapproved GLP-1 products obtained outside of the legitimate pharmacy system.
Other Peptides Marketed for Weight Loss
Beyond the FDA-approved GLP-1 drugs, some clinics offer other peptides for weight management. Sermorelin, which stimulates growth hormone release, is sometimes promoted for body composition changes, though its evidence base for meaningful fat loss is thin compared to GLP-1 medications.
Tesofensine is another compound generating attention. It works differently from GLP-1 drugs, acting instead on three brain chemical systems (dopamine, serotonin, and norepinephrine) to suppress appetite. Animal studies show it reduces daily food intake and produces sustained weight loss, with stronger effects in obese subjects than lean ones. Researchers have also found it can extend weight loss from other treatments and prevent the weight rebound that commonly follows dieting. However, tesofensine is not FDA-approved and remains investigational in the United States. Any clinic offering it is doing so outside the standard regulatory framework.
What the Process Looks Like in Practice
If you go the prescription route, here’s what to expect. After your consultation and any required lab work, your provider writes a prescription that you fill at a retail pharmacy (Walgreens, CVS, etc.) or through a mail-order pharmacy. The medication ships in a temperature-controlled package since these peptides need refrigeration. You start on a low dose and gradually increase over several weeks to reduce gastrointestinal side effects like nausea, which are common early on.
Many weight loss clinics and telehealth platforms handle the pharmacy coordination for you, shipping the medication directly to your door. Ongoing monitoring typically involves periodic check-ins, either in person or virtual, where your provider assesses your progress and adjusts the dose. Most treatment plans pair the medication with dietary and activity guidance, since the drugs work best as part of broader lifestyle changes.
The practical bottom line: the most reliable place to get peptides for weight loss is through a licensed prescriber and a licensed pharmacy. The brand-name drugs are expensive but increasingly accessible through manufacturer programs. Compounded alternatives are in legal limbo and carry quality uncertainties. Anything sold outside the medical system carries real risks that no price discount can justify.