MIC injections combine methionine, inositol and choline, usually with vitamin B12, and “Lipo-B” is a looser name for similar blends. No controlled trial shows they cause weight loss. B12 shots treat B12 deficiency, which long-term metformin use and some weight-loss surgeries can cause.[3][4] Telehealth programs we review list MIC-B12 from about $50 to $230 a month.
MIC-B12 is one of the most common add-ons on GLP-1 and wellness menus, and it is sold with words like “fat-burning,” “metabolism boost” and “energy.” This page separates what is in the shot from what each ingredient has been shown to do, explains who actually benefits from B12 injections, and lays out what the add-on costs. The short version: one ingredient has a proven medical use, for a specific deficiency, and none has a weight-loss trial behind it.
What is in a Lipo-B or MIC shot?
“MIC” is an abbreviation for three ingredients. Methionine is an essential amino acid you get from protein foods. Inositol is a sugar alcohol your body makes and that occurs in foods; as an oral supplement it is studied mainly for polycystic ovary syndrome. Choline is a nutrient your liver needs to package and export fat. Most MIC products add vitamin B12, either cyanocobalamin or methylcobalamin, and some “Lipo-B” or “lipotropic” blends add L-carnitine or other B vitamins. There is no standard formula. The milligrams of each ingredient depend on the compounding pharmacy, so ask for the exact label before you buy.
| Ingredient | What it does in the body | Evidence for weight loss as an injection | FDA status for compounding |
|---|---|---|---|
| Methionine | Essential amino acid; a building block of protein | None found | Not on FDA's 503A nomination categories list |
| Inositol | Cell signaling; oral form studied for PCOS | None found | Not on the categories list as inositol |
| Choline (as choline chloride) | Needed to move fat out of the liver | None found | Category 1, under evaluation (May 2026) |
| Vitamin B12, cyanocobalamin | Red blood cells and nerve function | None; treats deficiency | FDA-approved injection for B12 deficiency |
| Vitamin B12, methylcobalamin | Same vitamin, different form | None | Category 1, under evaluation (May 2026) |
Where does the word “lipotropic” come from?
“Lipotropic” describes a nutrient that keeps fat from building up in the liver, and choline is the classic example. The evidence for that is real but specific. In a controlled feeding study, 57 adults were put on a diet with almost no choline; 77% of men and 80% of postmenopausal women developed fatty liver or muscle damage, which reversed when choline was added back.[1] That shows the liver needs choline to work normally. It does not show that extra choline, injected on top of a normal diet, burns body fat. A deficiency cure and a fat-loss drug are different claims, and the marketing for lipotropic shots blurs them.
Is there any evidence MIC injections cause weight loss?
No controlled human evidence. We searched PubMed on October 2, 2026 for lipotropic or MIC injections and weight. The results were studies of injected or fed nutrients in goslings, broiler chickens and beef heifers, and no randomized trial in people trying to lose weight. MIC shots are often sold as an add-on to a prescription weight-loss drug or a diet plan, so any weight lost on the program cannot be credited to the shot. Inositol is the one ingredient with a real clinical literature, and it is oral and aimed at PCOS and insulin resistance, not injected fat loss; see our inositol evidence review and inositol vs metformin.
Who actually benefits from B12 injections?
People who are deficient, and especially people who cannot absorb B12 from food. The FDA-approved cyanocobalamin injection is indicated for “vitamin B12 deficiencies due to malabsorption,” such as pernicious anemia. Its label starts pernicious anemia at 100 mcg a day by intramuscular or deep subcutaneous injection for 6 or 7 days, then tapers to monthly injections for life. It also notes that needs above normal “can usually be met with oral supplementation.”[2] The NIH’s MedlinePlus lists the usual causes of deficiency: pernicious anemia, surgery that removes part of the stomach or small intestine (including some weight-loss operations), Crohn’s and celiac disease, long-term heartburn medicines, a strict vegetarian diet, and long-term metformin.[3]
Injections are not the only fix. A Cochrane review of three trials (153 people) found oral B12 at 1,000 or 2,000 mcg a day normalized blood levels about as well as intramuscular shots, at lower cost, though the evidence was rated low quality.[5] If your B12 is normal, more of it has not been shown to raise energy or speed weight loss.
| Situation | B12 deficiency risk | What usually happens |
|---|---|---|
| Normal diet, no absorption problem | Low | No shown benefit from extra B12 |
| Long-term metformin | Raised (DPPOS: low or borderline B12 in 20.3% vs 15.6% at 13 years) | Periodic B12 testing considered |
| Surgery that removes part of the stomach or small intestine | Raised | B12 shots, often monthly, may be needed long term |
| Pernicious anemia | High (cannot absorb B12 well) | B12 shots, often monthly, or high-dose oral B12 for some |
| Strict vegetarian or vegan diet | Raised | B12 pills may resolve it |
Do you need MIC-B12 on a GLP-1?
Being on semaglutide or tirzepatide is not, by itself, a reason for B12 shots. The reasons are the ones above. The one that overlaps most with GLP-1 patients is metformin. In the Diabetes Prevention Program Outcomes Study, adults on metformin 850 mg twice daily had low B12 more often than those on placebo at 5 years (4.3% vs 2.3%, P = 0.02), and combined low or borderline-low B12 was 19.1% vs 9.5% at 5 years and 20.3% vs 15.6% at 13 years. Each year of metformin raised the odds of deficiency (odds ratio 1.13 per year, 95% CI 1.06 to 1.20), and the authors recommended routine B12 testing for people on it.[4] For more on metformin itself, see our metformin review.
Some compounded GLP-1 prescriptions also mix B12 into the same vial. We found no trial showing that the addition changes weight loss or side effects. If fatigue or nausea on a GLP-1 is the reason you are considering MIC-B12, the more useful steps are in our guide to managing GLP-1 side effects, and a B12 blood test will tell you whether a shot would fix anything.
What do providers charge for MIC-B12?
Across the telehealth reviews we have published, standalone MIC-B12 or B12-with-MIC plans are listed from about $50 to about $230 a month. Some programs bill per four-week cycle rather than per calendar month, which adds a thirteenth charge each year, and some quote an “as low as” figure that may depend on a longer plan. At least one headline “longevity from” price we have seen turns out to be the MIC-B12 shot rather than the peptide or NAD+ product the page features. Check each review for the current figure and the billing period before comparing. Services that sell MIC-B12 alongside GLP-1s are compared on our GLP-1 providers page, and the cost of the underlying drugs is in our GLP-1 cost guide.
What should you ask before buying MIC-B12?
If you still want the add-on, five questions make one program comparable with another. First, how many milligrams of methionine, inositol and choline, and how many micrograms of B12, are in each milliliter, and how much is one dose? Second, which form of B12 is it, cyanocobalamin (the FDA-approved injectable) or methylcobalamin? Third, which pharmacy compounds it, and does it test batches for sterility? Fourth, is the price per calendar month or per four-week cycle, and does the advertised figure require a longer commitment? Fifth, will the prescriber check your B12 level first? A program that cannot answer the first and last questions is selling the shot, not treating a deficiency.
What are the side effects?
For B12 itself, the approved label carries the serious warning: “Anaphylactic shock and death have been reported after parenteral vitamin B12 administration,” and it recommends a test dose for people with suspected sensitivity.[2] That warning is one reason B12 injections are a prescription product. For MIC blends as a whole there is no systematic safety data, because they have never been through a controlled trial. Like every compounded injectable, the product is only as good as the pharmacy that made it, so ask which pharmacy compounds it and whether batches are tested for sterility.
The bottom line
MIC-B12 pairs one useful vitamin with three nutrients that have no weight-loss evidence as injections. B12 shots are a real treatment for a real deficiency, and metformin and some weight-loss surgeries make that deficiency more likely. For everyone else, a blood test costs less than a month of the add-on and answers the only question that matters: whether you are low.