The short answer
Often it has not: weight loss on any semaglutide slows and levels off after months. But with a compounded product, check the dose before you blame your body. A new vial concentration can change what your usual number of units delivers, a vial past 28 days or shipped warm may have lost quality, and FDA says salt forms such as semaglutide sodium are not the same ingredient as Wegovy or Ozempic.
At GLP-1 SOS, “my compounded semaglutide stopped working” usually arrives with a detail attached: a new pharmacy, a new vial, a box that arrived warm. The general reasons a GLP-1 seems to stop are covered in why did my GLP-1 stop working? This page is about what is different when the drug comes from a compounder, and how to check it in an afternoon.
At a glance
Three things to check
1
The dose in milligrams
Units on a syringe mean nothing without the vial’s concentration. A new concentration can halve or double your real dose.
2
The vial itself
FDA says discard a multi-dose vial 28 days after first use and never use one that arrived warm.
3
The calendar
Months in, a slower scale is the expected shape of treatment, not proof the drug failed.
What is actually happening
Start with the part that is the same for everyone. On approved semaglutide, weight falls fastest in the first months and then levels off. In the 68-week STEP 1 trial, adults on Wegovy 2.4 mg lost 14.9% of their body weight on average, and 86.4% lost at least 5%, but the curve flattened toward the end. A smaller body needs less food, and appetite pushes back, so the same dose does less to the scale over time. That is a plateau, and it happens on compounded and brand-name drugs alike; see when a plateau is normal.
Compounding adds questions the brand pens do not have. FDA’s alert on dosing errors explains that compounders sell semaglutide in different concentrations, a single compounder may offer several, and instructions are often written in syringe units, whose dose depends on concentration. Mix-ups in units, milliliters and milligrams led some patients to inject 5 to 20 times their intended dose. The same confusion can run the other way: if a new vial is half as strong and you draw your usual units, you get half the dose, and it feels like the drug stopped.
Lab note
With compounded semaglutide, the first question is not what changed in your body. It is what changed in the vial.
Then the product. Compounded drugs are not reviewed by FDA for safety, effectiveness or quality. FDA says some compounders use salt forms, semaglutide sodium or acetate, which are different active ingredients from the approved drugs, with no information on whether they act the same. It warns of fraudulent products labeled with real pharmacy names, of vials arriving warm, and that multi-dose vials should be discarded 28 days after first use even if the label says longer. Semaglutide is no longer on FDA’s drug shortage list, and since 2025 FDA has limited the compounding of copies of the approved drug, so a pharmacy switch or a reformulated product is worth asking about.
From FDA and the trials
The numbers behind it
28 days
after first use, FDA says to discard a multi-dose vial, even if medication remains (FDA, updated October 2026)
5–20x
the intended dose some patients injected after unit and concentration mix-ups with compounded semaglutide (FDA alert, 2024)
86.4%
of adults on Wegovy 2.4 mg lost at least 5% of their weight by week 68, as the curve leveled off (STEP 1, NEJM 2021)
Sources: FDA, Concerns with Unapproved GLP-1 Drugs, October 2026; FDA dosing-error alert, July 2024; Wilding et al., NEJM, 2021.
What to do
- Get your dose in milligrams. Ask the pharmacy or prescriber to write your dose as milligrams, milliliters and syringe units, along with the vial’s concentration. If you changed pharmacies or vials, compare the milligrams, not the units. Our page on side effects on compounded GLP-1s covers why this matters.
- Check the vial’s age and trip. Note the date you first punctured it. FDA says discard multi-dose vials 28 days after first use and do not use any GLP-1 that arrived warm or without enough ice. Use a new sterile needle and syringe each time.
- Ask exactly what is in it. Ask whether the product is semaglutide base or a salt form, and whether the formula, strength or pharmacy changed. If the vial looks different or the label has errors, FDA lists that as a red flag.
- Check the calendar and the missed doses. The approved Wegovy schedule climbs every 4 weeks from 0.25 mg to a maintenance dose; a long stretch at a low dose is not a failure. The Wegovy label says that after 2 or more missed weekly doses, escalation restarts at a lower dose.
- Look at the plate before the pen. Liquid calories and grazing slip past a GLP-1. If appetite is back on the last days before your shot, see why food noise comes back.
- Keep your daily routine steady while you sort it out. Changing several things at once hides the cause. If you take GLP-1 SOS Daily Gut Relief, keep the same 2 capsules with dinner; it supports digestive comfort and regular bowel movements and does not change how your medication works. A sudden jump in nausea after a new vial is a reason to call, not to push through.*
*GLP-1 SOS Daily Gut Relief supports regular bowel movements and digestive comfort. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Two kinds
Your checks, and your prescriber’s call
In your control
- Your dose written as mg, mL and units
- The vial’s concentration and first-use date
- How the last box arrived
- Missed or late doses, logged honestly
- Liquid calories and grazing
Your prescriber’s call
- Whether a dose step is due
- What a new concentration means for your units
- Whether the product or pharmacy should change
- Switching to an approved medication
- Judging true non-response
Never raise your own dose to make up for a vial you suspect. Ask first.
When to call your doctor
Call your prescriber the same day, or get urgent care, if:
- You think you injected more than your prescribed dose, or a new vial brought sudden severe nausea or vomiting
- You cannot keep liquids down or feel faint when you stand
- You have severe or lasting belly pain, sometimes spreading to your back
- You take insulin or a sulfonylurea and feel shaky, sweaty or confused
- The injection site is red, swollen and painful, or you develop a rash, swelling of the face or trouble breathing
A slower scale months in is usually normal. A dose you cannot verify is a question for your pharmacy and prescriber this week.
From the people behind the Lab
You do not have to figure this out alone.
GLP-1 SOS is the daily companion made for life on a GLP-1. Plain answers like this one, a support team that replies to real questions from real people, and daily formulas like GLP-1 SOS Daily Gut Relief, designed around the side effects that come with the medication. The GLP-1 Lab is our free education arm: no login, no paywall, no hype. Side effects are part of the road. Suffering through them is not.
Questions people also ask
Why is my compounded semaglutide not working anymore?
Most often it is the expected plateau, which happens on any semaglutide after months. With a compounded product, also check whether the vial concentration, formula or pharmacy changed, whether your dose in milligrams is what you think, and whether the vial is past 28 days from first use or arrived warm. Bring those answers to your prescriber before any dose change.
Can compounded semaglutide lose potency?
It can lose quality if it is handled badly. FDA says not to use injectable GLP-1s that arrive warm or without enough refrigeration, and to discard multi-dose vials 28 days after first use, even if the label allows longer. Compounded drugs are not reviewed by FDA for quality, so if a vial looks different from your last one, call the pharmacy.
I switched pharmacies and my semaglutide stopped working. Why?
The new vial may have a different concentration, so your usual units deliver a different number of milligrams. It may also be a different formula or a salt form, which FDA says is not the same ingredient as Wegovy or Ozempic. Ask both pharmacies for the concentration and your dose in milligrams, and compare them with your prescriber.
Should I increase my compounded semaglutide dose?
Not on your own. FDA has received reports of serious side effects from compounded doses above the approved labels and from dosing errors. If the scale has stalled, confirm the milligrams you are actually getting first; your prescriber can then decide whether a step up, staying put or switching products makes sense.
Is compounded semaglutide the same as Ozempic or Wegovy?
No. Compounded semaglutide is not FDA approved, so it is not reviewed for safety, effectiveness or quality before it reaches you. FDA lists claims that a compounded drug is the same as an approved one as a red flag. Some products use salt forms that FDA says are different active ingredients. The approved brands come in fixed doses in milligrams.
Sources (5)
- FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. U.S. Food and Drug Administration, updated October 2026.
- FDA alerts health care providers, compounders and patients of dosing errors associated with compounded injectable semaglutide products. U.S. Food and Drug Administration, July 2024.
- FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize. U.S. Food and Drug Administration, updated April 2026.
- Wegovy (semaglutide) injection and tablets, Prescribing Information. Novo Nordisk / FDA, revised June 2026.
- Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine, 2021.
Reviewed by the GLP-1 SOS editorial team · Education, not medical advice · Talk to your prescriber about your dose and your symptoms.
