Some compounded semaglutide and tirzepatide formulas add vitamin B12 or the amino acid glycine, partly for regulatory reasons and partly for hoped-for nutritional benefits. Evidence that these additions improve results is limited, and compounded products are not FDA-approved.
Some compounded semaglutide and tirzepatide products are prepared with an added ingredient, most often vitamin B12 (as cyanocobalamin) or the amino acid glycine. There are two kinds of reasons: a regulatory one, because FDA policy limits compounding of products that are essentially copies of approved drugs, and a clinical rationale, such as supporting nutrition while appetite is low. The honest summary is that evidence showing these additions improve weight results, energy or muscle is limited, and every compounded GLP-1 product, with or without an additive, is not FDA-approved.
According to the NIH Office of Dietary Supplements, vitamin B12 is a water-soluble vitamin found naturally in animal foods and added to some fortified foods. It is needed for nervous system function, healthy red blood cell formation and DNA synthesis. The Recommended Dietary Allowance for adults is 2.4 micrograms.
Some groups are more likely to run low, including older adults, people with pernicious anemia or other digestive conditions, people who have had gastrointestinal surgery such as weight-loss surgery, and people following vegan diets. Metformin, a common diabetes medication, may reduce B12 absorption, and acid-reducing medicines such as proton pump inhibitors can interfere with absorbing B12 from food. Deficiency can cause fatigue, nerve symptoms such as numbness or tingling, and a type of anemia.
The fact sheet notes that B12 does not have a tolerable upper intake level and is considered low in toxicity. It also states that B12 supplements do not appear to improve athletic performance in people who already have enough.
Glycine is one of the amino acids that make up proteins. MedlinePlus lists it as a nonessential amino acid, meaning the body can produce it even when food does not supply it. It is also listed as conditionally essential, a group that can become more important during illness or stress.
Both semaglutide and tirzepatide were on the FDA's shortage list for a period. The FDA later determined that both shortages were resolved, tirzepatide in December 2024 and semaglutide in February 2025. After that, FDA policy is that pharmacies generally should not compound drugs that are essentially copies of an approved product, unless a prescriber determines and documents that a change produces a significant difference for an identified patient.
Adding a second ingredient is one way formulas differ from the approved products. The FDA has signaled that an addition does not automatically settle the question. Its guidance gives the example of a semaglutide and vitamin B12 combination that may still be considered essentially a copy when it uses the same route and similar strengths to the approved products.
A 2024 review in JACCP, the Journal of the American College of Clinical Pharmacy, put it plainly: if an additive such as cyanocobalamin is added, the additive itself must provide the additional benefit for the patient.
The 2024 JACCP review describes claimed benefits for B vitamins and similar additives in obesity, energy levels and preventing nausea. Glycine has been discussed mainly in connection with preserving muscle mass. The next two sections look at what the evidence actually shows.
The 2026 review concluded that there is little justification for adding nutrients to injectable GLP-1 products in people without a laboratory-confirmed deficiency. It pointed instead to a joint advisory from several obesity and nutrition organizations that recommends monitoring for nutritional deficiencies and treating them.
The evidence for glycine is earlier-stage. The 2026 review describes animal studies in which glycine reduced muscle loss in a mouse cancer model and supported muscle regeneration in a mouse model of muscular dystrophy. The only human study it cites involved 27 people receiving hemodialysis, in whom oral glycine was associated with greater gains in fat-free mass than a comparison supplement. No patient data exist for glycine combined with semaglutide or tirzepatide. The review's authors described this as "at least some plausible unique potential," which is a reason for research rather than proof of benefit.
Compounded semaglutide and tirzepatide available through NewDay Wellness are formulated with B12 or glycine. Like all compounded medications, they are not FDA-approved, and the added ingredient has not been shown in clinical trials to improve weight results, energy or muscle preservation.
Some practical points:
There is no clinical trial evidence that it does. A real-world study of compounded semaglutide with B12 had no comparison group, so it could not separate the effect of B12 from semaglutide. Reviews in 2024 and 2026 found little justification for adding it in people without a confirmed deficiency.
B12 itself is considered low in toxicity and has no established upper intake limit, according to the NIH. The combined compounded product, however, has not been evaluated for safety in clinical trials, and compounded drugs are not FDA-approved.
Glycine has been proposed mainly for muscle preservation, based largely on animal studies and one small human study in people on dialysis. No studies have tested it alongside semaglutide or tirzepatide, so any benefit is unproven.
No. Compounded products are not FDA-approved with or without an additive. The FDA does not verify their safety, effectiveness or quality before marketing.
If you are weighing a compounded GLP-1, ask your prescriber what the added ingredient is meant to do for you specifically, whether a B12 test makes sense given your history, and how your nutrition will be monitored. A licensed provider can also explain how compounded options differ from FDA-approved brand products. This article is educational and does not determine eligibility for any treatment.
Written by the NewDay Wellness editorial team from the sources above and checked against them before publication, and medically reviewed by Dr. Sean Arora and Dr. Shannon Arora of Arora Health & Aesthetics; see our editorial standards. This article is educational and does not diagnose conditions, establish eligibility for any medication, or replace care from a licensed provider. Compounded medications are not FDA-approved.
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