What is inside
“Lipo-C” is a sales name for a “lipotropic” injection. Lipotropic is an old word for substances that help the liver move fat out. The core is three nutrients known as MIC: methionine, an amino acid from protein; inositol, a sugar-like molecule; and choline, a nutrient used to build cell membranes. The “C” adds L-carnitine, the molecule that carries fat into the parts of cells that burn it. None of these is a peptide. All four are found in food and made by the body.
There is no official recipe. Each pharmacy or seller decides how much of each goes in a vial. Nothing about it is standardised. The mixture is one of the most commonly compounded “wellness” injections in the United States, and it turns up in FDA inspection letters under names like “LIPOTROPIC INJ. SOL” and “LIPO (MIC)”. The label is the only description of what is inside. L-carnitine has its own page on this site.
The product is an aqueous mixture of four small, water-soluble molecules: L-methionine (an essential sulphur amino acid and the precursor of S-adenosylmethionine), myo-inositol (C6H12O6, 180.16 g/mol, NF monograph), choline (usually as choline chloride) and levocarnitine ((R)-3-hydroxy-4-trimethylammoniobutanoate, C7H15NO3, 161.20 g/mol). The “MIC” triad is a legacy of the mid-twentieth-century lipotrope literature, in which choline, betaine, myo-inositol, methionine and carnitine were identified as compounds that hasten removal of fat from the liver or reduce hepatic lipid deposition in animals, chiefly by supplying methyl groups and phosphatidylcholine for VLDL export and by supporting fatty-acid beta-oxidation (Fardet and Chardigny 2013).
No reference standard exists for the mixture. Concentrations are set by each 503A pharmacy or 503B outsourcing facility and by research-labelled sellers, and are not standardised; FDA’s warning letters name products only by ingredient. No published compatibility or stability data for the four in one solution were found. Pharmacokinetically, the Carnitor label reports a 17.4-hour terminal half-life for levocarnitine after intravenous dosing, while the intramuscular kinetics of methionine, inositol and choline given as a bolus are unpublished.
Who made it and when
No one invented Lipo-C as a product. The idea comes from nutrition research in the last century. Scientists found that animals fed diets short of choline or methionine built up fat in the liver, and that adding those nutrients cleared it. Choline, betaine, inositol, methionine and carnitine came to be called “lipotropes”. That is animal liver science. It was never a weight-loss programme.
The injection form grew out of compounding pharmacies, which mix drugs to order. The approved drug parts are older: levocarnitine was approved as Carnitor for carnitine deficiency, and methionine is a standard part of amino acid drips for people who cannot eat. Choline and inositol have no approved injection of their own. No company has developed the MIC mixture as a medicine, and no regulator has reviewed it.
No originator, patent or investigational programme exists for the combination. The scientific origin is the lipotrope concept: Fardet and Chardigny (2013) trace choline, betaine, myo-inositol, methionine and carnitine as the main lipotropes shown “very early on” to accelerate hepatic fat removal in animals, with magnesium, niacin, pantothenate and folate as indirect supporters, and note that human intervention studies are “practically non-existent”.
Component regulatory histories: levocarnitine is the active ingredient of Carnitor, approved for secondary carnitine deficiency from inborn errors of metabolism and, as the injection, for carnitine deficiency in end-stage renal disease patients on dialysis; L-methionine is a component of approved parenteral amino acid products such as Travasol 10% (initial approval 1984), which supplies 400 mg methionine per 100 mL as part of a 15-amino-acid mixture for parenteral nutrition; myo-inositol is the subject of an NF monograph; choline chloride was nominated for the 503A bulks list and sits in Category 1. The injectable lipotropic combination is a compounding-market product with no development history in the regulatory sense.
What the data say
No study has tested the four ingredients together, by injection or by mouth. Searches of the medical literature for methionine-inositol-choline injections found no clinical trial. The evidence for the parts is mostly negative or unrelated to weight.
L-carnitine has the best-known trial. In 2000, 36 overweight women took 2 g of L-carnitine twice a day or placebo for 8 weeks while walking four days a week. Body weight and fat did not change, and five women on carnitine dropped out with nausea or diarrhoea. Inositol has a 2022 pooled analysis of 15 trials: body mass index fell by about 0.4 units, a small change, mostly in women with polycystic ovary syndrome. Choline is needed to keep fat out of the liver, and a pilot study in 15 people fed through a vein found that adding choline cleared fatty liver. But that is deficiency correction, not fat loss. Methionine has no human weight or fat trial.
No trial of the combination, and no trial of any lipotropic injection, was identified. Component data: Villani et al. (2000) randomised 36 moderately overweight premenopausal women, pair-matched on BMI, to L-carnitine 2 g twice daily or lactose placebo for 8 weeks with supervised walking; among completers (13 vs 15) there were no significant changes in total body mass, fat mass or resting lipid utilisation and no between-group differences, and 5 carnitine-group participants withdrew with nausea or diarrhoea. Zarezadeh et al. (2022) pooled 15 controlled trials of oral inositol and found a weighted mean BMI reduction of 0.41 kg/m2 (95% CI −0.78 to −0.04) with high heterogeneity (I2 = 73.9%), larger in PCOS and overweight subgroups.
Choline’s evidence concerns hepatic steatosis, not adiposity: NIH ODS reports that in a depletion study 37 of 57 adults on under 10% of the adequate intake developed liver dysfunction, and that in a 15-patient pilot on total parenteral nutrition adding 2 g choline resolved NAFLD in all treated patients and none of the controls, while stating that only limited data support choline for treating NAFLD. Cerletti et al. (2020), a double-blind randomised trial of a six-component mixture including choline and phosphatidylcholine in 113 NAFLD subjects for 3 months, found no difference from control in liver enzymes or metabolic variables. No human study of methionine for weight or hepatic fat outside parenteral nutrition was found, and Fardet and Chardigny (2013) describe human lipotrope intervention studies as practically non-existent.
Ingredient: Methionine
Methionine is one of the nine essential amino acids. The body cannot make it, so it must come from protein foods. Cells turn it into a molecule called SAMe, which hands out “methyl groups”, small chemical tags used in thousands of reactions. One of those reactions builds phosphatidylcholine, the main fat in cell membranes and in the particles that carry fat out of the liver. That is why methionine counts as a lipotrope.
In animals, a diet short of methionine and choline is a standard way to cause fatty liver. That does not mean extra methionine burns fat in a person eating normally. No human trial of methionine for weight or fat loss was found. Its only injectable use in approved medicine is as one of 15 amino acids in nutrition drips such as Travasol, for people who cannot eat. Because it is part of an approved drug, pharmacies may use it in compounding.
L-methionine is an essential amino acid and the precursor of S-adenosylmethionine, the universal methyl donor for phosphatidylethanolamine N-methyltransferase-mediated phosphatidylcholine synthesis, DNA and protein methylation and, via transsulphuration, cysteine and glutathione synthesis. The lipotropic attribution rests on rodent work: the methionine- and choline-deficient diet is a standard model of steatohepatitis, and methionine repletion reverses it (Fardet and Chardigny 2013).
No randomised human trial of methionine for adiposity or hepatic fat was identified. The approved parenteral use is nutritional: Travasol 10% supplies 400 mg L-methionine per 100 mL within a balanced 15-amino-acid formulation indicated as a source of amino acids for parenteral nutrition when oral or enteral feeding is not possible. As a component of an approved drug, L-methionine satisfies section 503A(b)(1)(A)(i) on its own; it does not appear on FDA’s 503A category lists. Injection-site tolerability, pharmacokinetics and safety of bolus intramuscular methionine outside balanced infusions are unpublished.
Ingredient: Inositol
Inositol is a sugar-like molecule; the form in these products is myo-inositol. The body makes it and it is in many foods. Inside cells it sits in the membrane and in the chemical signals that answer insulin. Its research is almost all oral and almost all in women with polycystic ovary syndrome, where it is studied for insulin resistance and hormone levels.
A 2022 review pooled 15 trials of inositol by mouth and found body mass index fell by about 0.4 units, a small effect that was larger in women with PCOS. No trial of injected inositol was found. Inositol is not on the FDA’s compounding category lists. It has an official monograph in the National Formulary, which is one route by which an ingredient qualifies for use by compounding pharmacies.
Myo-inositol (cis-1,2,3,5-trans-4,6-cyclohexanehexol, C6H12O6, 180.16 g/mol; NF monograph specification 97.0-102.0% on the anhydrous basis) is a constituent of membrane phosphoinositides and of inositol-phosphoglycan insulin second messengers, which underlies its study in insulin-resistant states. Its lipotropic classification derives from the same animal liver literature as choline and methionine.
Human data are oral. Zarezadeh et al. (2022): 15 controlled trials, weighted mean BMI difference −0.41 kg/m2, heterogeneity explained partly by duration, baseline BMI, age, isomer and dose, with myo-inositol more effective than other forms and the effect concentrated in PCOS and overweight participants. No pharmacokinetic or clinical study of parenteral inositol was identified. Regulatory: myo-inositol has an applicable NF monograph and therefore meets a 503A eligibility criterion without appearing on the bulks list; it is absent from FDA’s category lists, where only the unrelated ester inositol hexanicotinate appears (Category 3).
Ingredient: Choline
Choline is a nutrient the body uses to build cell membranes, to make the nerve signal acetylcholine and to package fat for export from the liver. The liver makes some, but not enough, so food must supply the rest. Most Americans eat less than the recommended amount, yet true deficiency is very rare in healthy people. When it does occur, fat builds up in the liver.
That liver link is the reason choline is in this blend. In one study, 37 of 57 adults on a near-choline-free diet developed liver problems, and in 15 people fed through a vein, adding choline cleared fatty liver. That is fixing a shortage, not burning body fat; no trial shows choline reduces weight in people who eat enough of it. Too much choline causes a fishy body odour and low blood pressure, and gut bacteria turn it into TMAO, a compound linked to heart disease. The FDA lists choline chloride as “under evaluation” for compounding.
Choline is a precursor of phosphatidylcholine, sphingomyelin and acetylcholine, and via betaine a methyl donor; phosphatidylcholine is required for VLDL assembly, so deficiency impairs hepatic triglyceride export and produces steatosis. Adequate intakes were set on prevention of liver damage measured by serum ALT, and the adult daily value is 550 mg. NIH ODS summarises the human evidence as a depletion study (liver dysfunction in 37 of 57 adults on under 10% of the AI for up to 42 days, reversed on repletion) and a 15-patient TPN pilot in which 2 g supplemental choline resolved NAFLD in all treated patients, while stating that only limited data support choline for treating NAFLD. A randomised trial of a choline-containing nutraceutical mixture in 113 NAFLD subjects showed no efficacy (Cerletti et al. 2020).
Adverse effects at high intake are fishy body odour, vomiting, excessive sweating and salivation, hypotension and hepatotoxicity; the tolerable upper intake levels were derived from hypotension and body odour, and choline raises TMAO production dose-dependently, with higher intake associated with mortality in two large US cohorts. No clinically relevant drug interactions are known. Choline chloride is in 503A Category 1 (under evaluation) and choline bitartrate in Category 3 on FDA’s list updated 2026-05-14; no approved parenteral choline product was identified.
Ingredient: L-carnitine
L-carnitine is the shuttle that carries long fat chains into mitochondria, the cell’s power plants, so they can be burned. The body makes it from two amino acids, and red meat supplies more. Its drug name is levocarnitine. The FDA has approved it, as Carnitor, for people whose bodies cannot make or keep carnitine, and for people on kidney dialysis who lose it during treatment. It is also sold as a dietary supplement.
For fat loss, the evidence is negative. In the 2000 trial of 36 overweight women, 2 g twice a day for 8 weeks with walking did not change weight or body fat, and five women left because of nausea or diarrhoea. The Carnitor injection label warns of severe allergic reactions, mostly in dialysis patients, and of seizures. Because it is an approved drug, pharmacies may use it in compounding, but they may not make copies of Carnitor while it is available.
Levocarnitine enables mitochondrial beta-oxidation of long-chain fatty acids via the carnitine palmitoyltransferase shuttle and buffers the acyl-CoA pool. Carnitor injection is indicated for secondary carnitine deficiency from inborn errors of metabolism and for prevention and treatment of carnitine deficiency in end-stage renal disease patients on dialysis; the label records a 17.4-hour terminal half-life after intravenous dosing.
Weight-loss evidence is negative: Villani et al. (2000) found no change in total body mass, fat mass or resting lipid utilisation with 2 g twice daily for 8 weeks plus aerobic training in overweight women, with gastrointestinal drop-outs. The Carnitor injection label lists no known contraindications; warnings cover serious hypersensitivity reactions including anaphylaxis, laryngeal edema and bronchospasm (mostly in dialysis patients, sometimes within minutes), post-marketing seizures with greater frequency or severity in patients with seizure disorders, and TMA/TMAO accumulation with high oral doses in severely compromised renal function; adverse reactions include injection-site reactions, headache, pain, gastrointestinal symptoms and transient nausea and vomiting; INR monitoring is advised with warfarin. Regulatory: levocarnitine is the active ingredient of an approved drug, so it meets a 503A criterion, subject to the prohibition on compounding essentially copies of a commercially available product; it is absent from FDA’s category lists, where only acetyl-L-carnitine appears (Category 1).
Why researchers might study these together
The idea is “help the liver handle fat, then help the body burn it”. Methionine and choline supply the chemical tags and building blocks that package fat for export from the liver. Inositol sits in the same membrane chemistry. Carnitine then carries fat into the cell’s furnaces. On paper, the four cover the whole journey of a fat molecule. In practice, this is a hypothesis built from animal liver studies, and no one has tested it in people.
The gap is large. The animal work showed that adding these nutrients fixes fatty liver caused by taking them away. It did not show that extra amounts speed fat burning in a well-fed animal, let alone a person. The one carnitine weight trial was negative. A choline-containing mixture did nothing for fatty liver in a randomised trial. And injecting the mixture into muscle or under the skin has never been compared with swallowing the same nutrients, which are all available in food.
The rationale is the lipotrope hypothesis: methionine (via S-adenosylmethionine) and choline supply the methyl groups and phosphatidylcholine required for hepatic VLDL assembly and triglyceride export, inositol contributes to the same phospholipid pool, and carnitine supports beta-oxidation of the mobilised fatty acids (Fardet and Chardigny 2013). Each link is established in deficiency models, not as a pharmacological effect in replete individuals, and Fardet and Chardigny note that human intervention studies are practically non-existent.
No preclinical or clinical study of the four-component mixture, or of any lipotropic injection, was identified. The available human data on individual components are either negative for adiposity (Villani et al. 2000 for carnitine), modest and confined to oral use in specific populations (Zarezadeh et al. 2022 for inositol), or limited to correction of deficiency-induced steatosis (choline, NIH ODS), and a randomised trial of a choline-containing mixture in NAFLD was negative (Cerletti et al. 2020). Whether parenteral bolus administration offers any pharmacokinetic advantage over dietary intake for these nutrients has not been studied.
Regulatory picture
Approval: no regulator has approved a methionine-inositol-choline-carnitine injection, for weight loss or anything else. Two of the parts are in approved medicines: levocarnitine (Carnitor) for carnitine deficiency, and methionine as one amino acid in nutrition drips. Choline and inositol have no approved injection.
Compounding (pharmacies mixing their own drugs): the FDA judges each ingredient on its own, and each of the four has a route to eligibility. Methionine and levocarnitine are parts of approved drugs. Inositol has an official monograph. Choline chloride is “under evaluation” (Category 1), which means the FDA has said it does not intend to act against its use while it decides. The mixture itself has no status. The MIC injection is widely compounded: FDA letters to pharmacies and outsourcing facilities in 2020, 2025 and 2026 mention lipotropic and “LIPO (MIC)” products, citing missing prescriptions, contamination-control failures and incomplete labels. None of those letters says the formula is unsafe; they are about how it was made and sold.
Approval: none for the combination. Levocarnitine and L-methionine are active ingredients of approved drugs (Carnitor; parenteral amino acid formulations such as Travasol 10%) for unrelated indications; no approved parenteral choline or inositol product was identified.
Compounding: under section 503A(b)(1)(A)(i), each bulk substance must have an applicable USP or NF monograph, be a component of an approved drug, or appear on the 503A bulks list (21 CFR 216.23). Levocarnitine and L-methionine qualify as components of approved drugs, subject to the section 503A(b)(1)(D) prohibition on essentially copies of commercially available products in levocarnitine’s case; myo-inositol qualifies through its NF monograph; choline chloride is in 503A Category 1 on FDA’s list updated 2026-05-14, meaning it is under evaluation and covered by the interim policy’s enforcement discretion rather than a final determination, while choline bitartrate is in Category 3. The blend therefore has no status of its own and rests on one ingredient whose status is provisional; this article records compounding as unknown.
Enforcement: FDA’s 2020-09-17 warning letter to Randol Mill Pharmacy cited a “LIPOTROPIC INJ. SOL” made without valid patient-specific prescriptions; its 2025-04-02 letter to Empower Pharma, a 503B outsourcing facility, cited a methionine, choline chloride and cyanocobalamin injection in connection with an inadequate investigation of fungal contamination on an operator’s fingertips during filling; and its 2026-01-20 letter to GenoGenix LLC listed a “LIPO (MIC) + B” product whose label lacked the established name and dosage form. These document how widely the product is compounded and the manufacturing findings against particular facilities; none evaluates the formula’s safety or efficacy.
