L-Carnitine Injection Dosage: FDA Label vs Off-Label Fat Loss
L-carnitine injection dosage: the FDA label dose for diagnosed deficiency, kept separate from the common off-label fat-loss protocol clinics use.
The short version
The FDA label for CARNITOR gives a weight-based IV dose for diagnosed carnitine deficiency. It is up to 50 mg/kg every 3-4 hours in a metabolic crisis, or 10-20 mg/kg after each dialysis session. That is a different figure from the 200-2,000 mg per injection, 1-3 times a week, that clinics describe for the separate, off-label fat-loss use. This page states both, clearly labelled, and does not blend them into one number.
- FDA label dose (deficiency): 50 mg/kg slow IV bolus or infusion every 3-4 hours, up to 300 mg/kg/day, in metabolic crisis.
- FDA label dose (dialysis): 10-20 mg/kg IV after each hemodialysis session.
- Off-label fat-loss dose (not FDA-reviewed): 200-2,000 mg per injection, 1-3 times a week. Two clinic sources disagree substantially.
- The two uses are not interchangeable, and this page never mixes their numbers.
L-Carnitine (injection) dosage chart
L-Carnitine (injection) is FDA-approved only for a specific use; research vials are sold for others. Units on a U-100 insulin syringe across the common off-label range - common practice, not the label dose - by vial size.
200 mg vialwith 10 mL water
| Dose | Units | Volume | Doses per vial |
|---|---|---|---|
| 200 mg | over 100 units | 10 mL | 1 |
Full 200 mg vial page: other water volumes, mixing, storage →
U-100 insulin syringe (100 units = 1 mL), to the nearest half unit. Arithmetic only. Other numbers: peptide calculator.
L-carnitine injection has two dosing pictures that do not mix. One is an FDA-approved label dose for diagnosed carnitine deficiency. The other is a separate, off-label protocol clinics use for fat loss. This page states both, clearly labelled and sourced separately. For what each use is and is not backed by, see the main L-carnitine injection guide.
US legal status - FDA-approved · prescription only
CARNITOR (levocarnitine) injection is FDA-approved, prescription-only, for diagnosed carnitine deficiency. The off-label fat-loss dose below is the same prescription substance used outside that approval, not a separately reviewed product.
L-carnitine dosage for diagnosed deficiency: the FDA label
For acute metabolic crisis, the label states 50 mg/kg given as a slow 2-3 minute bolus injection or by infusion. It is repeated every 3-4 hours (never less than every 6 hours). A loading dose is sometimes given, followed by an equivalent dose spread over the following 24 hours, up to a maximum of 300 mg/kg/day.
For patients on hemodialysis, the label describes a starting dose of 10-20 mg/kg dry body weight, as a slow 2-3 minute bolus injection after each dialysis session. It is sometimes reduced (for example to 5 mg/kg) after 3-4 weeks, based on response.
Both are intravenous, weight-based doses for a diagnosed condition, set and monitored by a prescriber. Neither is a self-directed dose.
L-carnitine dosage: the off-label fat-loss protocol
Separately from the approved deficiency dose above, clinic and vendor dosing guides describe 200-2,000 mg per injection, 1-3 times a week, by intramuscular or subcutaneous injection. This is common practice for people without diagnosed deficiency, not a dose FDA has reviewed for fat loss.
Common protocol
What is commonly used. For its approved use, the dose is the one on the FDA label. Sources differ, so the ranges below span them.
- Dose per administration
- 200-2000 mg
- How often
- 1-3 times a week by intramuscular or subcutaneous injection, commonly in the morning or before a workout
- Route
- Intramuscular injection
- Cycle length
- No set length in common use
- Timing
- Morning or pre-workout, framed around supporting fatty-acid transport during activity. Neither source gives a specific cycle length.
This is the off-label, non-deficiency 'fat loss' use sold by weight-loss and aesthetic clinics, distinct from the FDA-approved CARNITOR indication (diagnosed carnitine deficiency), which is IV-only and dosed very differently - see the compound record and the dosing page. Sources disagree sharply on how much to inject (200-500 mg vs 500-2000 mg per shot), so the range spans them.
Plan a cycle in the protocol builder or work out injection volume in the dosage calculator.
What the human trial evidence shows for fat loss specifically
The strongest human evidence for L-carnitine and weight loss is a meta-analysis of 37 randomized controlled trials. Nearly all used oral L-carnitine rather than injection. It found that L-carnitine significantly decreased body weight and fat mass Talenezhad 2020 - Talenezhad N, Mohammadi M, Ramezani-Jolfaie N et al. Effects of l-carnitine supplementation on weight loss and body composition: A systematic review and meta-analysis of 37 randomized controlled clinical trials with dose-response analysis. Clin Nutr ESPEN. 2020;37:9-23., in the references below.
Only the body-weight effect held when the analysis was restricted to high-quality trials. The dose-response link was seen for body weight, not for BMI, waist circumference or body fat percentage. The largest effect was around 2,000 mg per day taken orally Talenezhad 2020 - Talenezhad N, Mohammadi M, Ramezani-Jolfaie N et al. Effects of l-carnitine supplementation on weight loss and body composition: A systematic review and meta-analysis of 37 randomized controlled clinical trials with dose-response analysis. Clin Nutr ESPEN. 2020;37:9-23., in the references below.
That is real RCT-level evidence for a modest effect. It comes from swallowed capsules in general adult populations, not from the injectable product the off-label protocol above describes. No trial in my registry tested the injectable fat-loss protocol itself.
What is not established
- No FDA-approved dose exists for fat loss, at any dose, by any route. The approval covers diagnosed deficiency only.
- The off-label protocol above is clinic marketing, not a trial finding. The two sources behind it disagree by a factor of roughly four on how much to inject.
- The oral-trial evidence does not transfer to the injectable product used off-label. The route and population differ, and there is no injectable trial to check it against.
Who should not use it
For the approved deficiency use, a prescriber managing that diagnosis makes dosing and monitoring decisions. For the off-label fat-loss use, no FDA-reviewed contraindication list exists, because that specific use has not been reviewed. Nobody should self-direct a prescription injectable around a current medical condition, medication or pregnancy.
L-carnitine injection side effects and risks
That safety record comes from the approved indication’s trial and postmarketing data. The off-label fat-loss population typically gets smaller doses by IM or subcutaneous injection rather than the approved IV route. It has no comparable FDA-reviewed safety data of its own.
Related
- L-carnitine injection: FDA-approved use vs off-label fat loss
- Research peptides and the law
- Are peptides safe?
L-Carnitine (injection) dosage calculator
Preset to a 5 mg vial and 200,000 mcg, the low end of the common protocol. Enter your own vial size, water and dose to get the syringe units to draw.
Your vial
Printed on the vial. There is no standard size - enter what yours says.
This changes how much you draw - never how many doses the vial holds.
100 units per mL. 1 unit = 0.01 mL. This is what almost every insulin syringe sold is, in every barrel size.
Capacity only. A 1 mL U-100 syringe holds 100 units - the scale decides that, not the barrel.
Draw this much
= 80 mL on a 1 mL U-100 syringe
- Concentration
- 2,500 mcg/mL
- Exact volume
- 80 mL
- Dose you actually get
- 200,000 mcg
- Doses per vial(unaffected by water volume)
- 0
- This dose needs 8000 units, but a 1 mL U-100 syringe only holds 100. It will not fit in one draw - use less water, or a larger barrel.
Where to get L-Carnitine (injection) legally
L-Carnitine (injection) is an FDA-approved prescription medicine, so the legal route is a licensed prescriber, in person or by telehealth, and a licensed pharmacy.
How telehealth prescribing works, what it costs and what to check: telehealth peptide prescribing.
Common questions
What is the FDA-approved L-carnitine injection dose?
For acute metabolic crisis from carnitine deficiency, the label states 50 mg/kg given as a slow 2-3 minute bolus injection or by infusion. It is repeated every 3-4 hours (never less than every 6 hours), up to a maximum of 300 mg/kg/day. For dialysis patients, the label describes a starting dose of 10-20 mg/kg dry body weight as a slow bolus after each hemodialysis session, sometimes reduced after 3-4 weeks.
What is the off-label fat-loss L-carnitine injection dose?
Clinic dosing guides I reviewed describe 200-2,000 mg per injection, by intramuscular or subcutaneous route, 1-3 times a week. This is common practice at weight-loss and aesthetic clinics, not FDA-reviewed. The two clinic sources behind the figure disagree substantially: one describes 200-500 mg, the other 500-2,000 mg per injection.
Can I use the deficiency dose for fat loss, or vice versa?
No. They are different uses of the same drug, evaluated separately. The deficiency dose is calibrated to a diagnosed metabolic condition and given IV in a clinical setting. The off-label fat-loss dose is a much smaller amount used in a different population, with no FDA review behind it. This page does not support mixing the two figures.
Is there an FDA-approved dose for fat loss?
No. FDA has not approved levocarnitine, at any dose, for fat loss or weight loss in a person without diagnosed carnitine deficiency.
What are the main risks?
FDA's label documents serious hypersensitivity reactions (anaphylaxis, laryngeal edema, bronchospasm), some within minutes of IV administration, and postmarketing reports of seizures. Those come from the approved-indication population. The off-label fat-loss population has no comparable FDA-reviewed safety record.
When should I stop and get medical care?
Get emergency care (call 911 in the US) for signs of a severe allergic reaction - swelling of the face, lips, tongue or throat, difficulty breathing. Also get emergency care for any severe or rapidly worsening symptom after an injection. Call Poison Control at 1-800-222-1222 for an unknown or excessive amount of anything sold as L-carnitine.
References (3 sources)
Bibliographic detail is fetched from PubMed, not written by me - so a citation here cannot drift from the paper it names. Study design comes from PubMed's own tags rather than my judgement.
- 1.Talenezhad N, Mohammadi M, Ramezani-Jolfaie N et al. Effects of l-carnitine supplementation on weight loss and body composition: A systematic review and meta-analysis of 37 randomized controlled clinical trials with dose-response analysis. Clin Nutr ESPEN. 2020;37:9-23.Meta-analysisPMID 32359762
- 2.DailyMed - CARNITOR (levocarnitine) injection, solution, full prescribing information, including the dosage and administration section.- DailyMed, US National Library of Medicinelabel
- 3.America's Poison Centers - confirms 1-800-222-1222 as the national Poison Control number, free and confidential, 24 hours a day.- America's Poison Centersother