Tirzepatide With Glycine, B6 or Niacinamide

Compounded tirzepatide with glycine, vitamin B6 or niacinamide is ordinary compounded tirzepatide with a second ingredient mixed in by the pharmacy. The addition is an amino acid or a vitamin, not a second weight-loss drug.^[9][10][11] No published human study shows it does anything for you in this product, and FDA has said the safety and effectiveness of combining semaglutide with other ingredients has not been established.^[3] What it changes is the product you are buying, and sometimes the price.

What is in the vial

A compounded vial labeled “tirzepatide/glycine” or “semaglutide/pyridoxine” holds two ingredients, sometimes three, because a pharmacy combined them. It is not a brand-name product with something extra in it. Compounded drugs are not FDA-approved, which means nobody at FDA checks their safety, effectiveness or quality before they reach you.^[5]

These combinations are common. Pharmacy researchers who searched compounder websites in early 2025 found 33 distinct compounded semaglutide and tirzepatide products, and 48 percent paired the GLP-1 with cyanocobalamin, glycine, niacinamide, docusate or ondansetron.^[6] A 2025 secret-shopper study of 75 weight-loss clinics and medical spas in West Virginia and Oklahoma found 42 of them (56.0 percent) offering compounded GLP-1s combined with B vitamins.^[8] An earlier survey of 93 Colorado websites found B vitamin combinations on 8 and glycine on 1.^[7]

Glycine, B6 and niacinamide: what each one is

What the evidence shows for each combination

Nothing, in people. We searched PubMed for human studies of glycine, vitamin B6 or niacinamide given with semaglutide or tirzepatide, including searches aimed at muscle, lean mass and nausea. None tested the additive against the GLP-1 alone, and none measured a benefit. The hits were animal studies, lab studies of metabolism and reviews.

The published record that does exist is critical. The authors of the 33-product survey wrote that they “found little justification for adding nutrients” to injectable semaglutide or tirzepatide.^[6] FDA, writing about semaglutide, named pyridoxine (vitamin B6) among the ingredients compounders add and said the safety and effectiveness of such combinations has not been established.^[3] That statement is about semaglutide. FDA has not published a parallel one about tirzepatide on the pages we read, and none of those pages mentions glycine or niacinamide.

Why the additive matters under FDA’s compounding rules

A state-licensed pharmacy compounding under section 503A may not compound, regularly or in inordinate amounts, drugs that are essentially copies of a commercially available drug product.^[2] FDA says it treats a compounded drug as essentially a copy when it has the same active ingredient as an approved product at the same, a similar or an easily substitutable strength, and can be used by the same route. The exception is a change that a prescriber determines and documents produces a significant difference for an identified individual patient.^[1]

Adding a second ingredient does not get a product out of that test on its own. FDA says a compounded drug combining active ingredients can still be essentially a copy when those ingredients are each in commercially available products at similar strengths and by the same route, and it used semaglutide with vitamin B12 as its worked example.^[1] We cover that example in the B12 article. FDA has not said, on any page we read, how that test applies to glycine, B6 or niacinamide.

Two more lines from FDA set the limits. It does not intend to act on the copy restriction against a compounder that fills four or fewer prescriptions of a product in a calendar month.^[1] And outsourcing facilities under section 503B may compound from bulk ingredients only when FDA has put that ingredient on its 503B bulks list or has the finished drug on its shortage list. FDA states that tirzepatide and semaglutide are on neither list.^[1] An added vitamin or amino acid does not change that.

Sellers on our register that list these additives

16 sellers in our register name one of these additives in a price listing or feature list: 9 for glycine, 6 for vitamin B6 and 2 for niacinamide. The price column is each seller’s lowest GLP-1 price we list, whichever formula it belongs to. The last column says whether that cheapest listing is itself the additive formula.

The additive does not carry a consistent premium. At one seller in the table the glycine formula costs more than its plain formula, at another it costs less, and a third charges the same for its B12 and glycine versions. Compare the formula you are offered with the seller’s plain version, if it has one, before you assume the extra ingredient costs more or is worth more. Full pricing for each seller is on its review page, and the compounded tirzepatide rankings compare them side by side.

Questions to ask the pharmacy

1. How much of each ingredient is in one milliliter? A combination vial has two strengths on its label. Make sure you know which number is the tirzepatide. Our vial label reader walks through the arithmetic.
2. How many units on my syringe is my dose? FDA has received adverse event reports, some involving hospitalization, that may be related to patients measuring and injecting the wrong dose of compounded semaglutide.^[4]
3. Is there a version without the additive, and does it cost less? Some sellers in the table list both.
4. Which pharmacy made it, and is it state-licensed? FDA’s advice is to fill a prescription at a state-licensed pharmacy.^[4]
5. What is the beyond-use date, and how should I store it? Only 18 percent of the products in the 33-product survey stated a beyond-use date and storage conditions.^[6]

For more on reading a compounded vial, see what is in a compounded GLP-1 vial. For what people report on compounded tirzepatide, see compounded tirzepatide side effects, and for how compounded and brand products differ, compounded vs brand semaglutide.