Fat Loss · 600mg/ml × 10 vials
In plain terms: L-Carnitine is a research compound — injectable, fast-acting and well studied.
L-Carnitine is a conditionally essential amino acid derivative that acts as the obligate carrier for long-chain fatty acids across the inner mitochondrial membrane. Without carnitine, long-chain fatty acyl-CoAs cannot enter the mitochondrial matrix where beta-oxidation happens, so fat literally cannot be burned for ATP at the mitochondrial level. The mechanism runs through the carnitine palmitoyltransferase shuttle: CPT1 on the outer mitochondrial membrane swaps the CoA group on a fatty acid for carnitine, the resulting acylcarnitine crosses via carnitine-acylcarnitine translocase, and CPT2 on the inner membrane swaps carnitine back out for CoA so beta-oxidation can proceed. Free carnitine is recycled back across the membrane to repeat the cycle. The body synthesizes about 25% of its carnitine needs in the liver and kidney from lysine and methionine, and gets the remaining 75% from dietary red meat and dairy; vegetarians/vegans run lower tissue stores.
The clinical and bodybuilding interest in injectable L-Carnitine comes from one stubborn pharmacokinetic problem: oral bioavailability is brutally low, around 14-18% from supplemental doses (and only 54-87% from food). Most of an oral dose is fermented by gut bacteria into trimethylamine before it can be absorbed, which is also where the cardiovascular TMAO concern originates. IM and IV injection bypass GI absorption entirely and push plasma free carnitine 5-10x higher than oral dosing can achieve, which is why injectable l-carnitine is the route of choice for cutting/contest prep, dialysis-associated carnitine deficiency (the only FDA-approved indication for IV levocarnitine), and the broader bodybuilding "fasted cardio pre-load" protocol. ALCAR (acetyl-l-carnitine) is the brain-penetrant form used as a nootropic; propionyl-l-carnitine is the cardiac/peripheral vascular disease form; levocarnitine is the pharmaceutical USP form used in PP's LC600 vials. The injectable bypasses the TMAO conversion almost entirely at clinical doses because the substrate never sits in the gut.
Typical dose ranges by experience level — educational reference. Message us and we tailor it to you.
Beginner protocol mirrors what most contest-prep coaches use as a "starter" carnitine dose. Inject pre-fasted-cardio (30-60 min before) on training days for the best subjective feel. Vegetarians/vegans typically feel the effect earlier (1-2 weeks) because baseline tissue stores are lower. Pair with a clean diet; carnitine without a caloric deficit doesn't drive scale loss, it just makes existing cardio more efficient at fat substrate.
This is the "working dose" for bodybuilders running carnitine during a cut. 600 mg/day IM matches the plasma levels of about 4 g/day oral (which most users can't tolerate due to GI sides and TMAO smell). Some users split into 0.5 ml AM (pre-cardio) and 0.5 ml PM (pre-training) for steadier plasma levels, especially during contest prep peak weeks. Tissue saturation takes 8-12 weeks regardless of frequency; running shorter than that and expecting visible results is a common mistake.
Top-end protocol for contest week and late-prep. Some IFBB-level coaches push 2-3 g/day IM in the final 4 weeks; doses above 2 g/day require splitting into 2-3 daily injections because IM injection volume above 2 ml at one site is uncomfortable and absorption flattens. Pair with PLC (propionyl-l-carnitine) or ALCAR if the customer wants peripheral vascularity or cognitive support arms, but those aren't in PP's catalog as standalone injectables. Advanced users almost always stack with a fat oxidation chain (clen, T3, yohimbine, or a GLP-1) since carnitine alone is not a primary fat loss driver, it's an efficiency multiplier.
Straight talk — what people actually report, and what the studies measured.
Peer-reviewed studies and clinical guidelines — tap any to read the source.
](https://www.clinicalnutritionespen.com/article/S2405-4577(20)30053-X/abstract) - 1.2 kg additional weight loss vs placebo over 12 weeks, modest effect
Read study ↗PubMedL-carnitine for weight management updated meta-analysisoverweight/obese subgroups only, dose-response analysis
Read study ↗PubMedPharmacokinetics of oral L-carnitine in humans, Rebouche 200414-18% bioavailability from supplements, gut bacterial metabolism
Read study ↗PubMedCarnitine transport and fatty acid oxidation, Longo et alCPT1/CPT2 shuttle mechanism review
Read study ↗PubMedIntestinal microbiota TMAO production from L-carnitine, Koeth Nature Medicine 2013the seminal paper linking dietary carnitine to TMAO and atherosclerosis
Read study ↗PubMedLevocarnitine in hemodialysis patients, Hurot meta-analysisFDA-approved indication review
Read study ↗Aggregated sentiment from public forums & socials — real-world reports, not individual endorsements.
Sting on injection: most-reported sensation, manageable with slow injection and warming the vial to room temp
Cleaner-feeling cardio / longer endurance: most-reported subjective effect, especially in vegetarians and during fasted-state work
Body odor / fishy smell on breath or skin: reported but much less than oral users describe; some users notice nothing
Energy lift / mood lift: less consistent than B12; ALCAR (oral) drives this more than levocarnitine injection
"I felt nothing on scale": common honest report when used standalone without a caloric deficit; carnitine doesn't create a deficit, it just makes oxidation more efficient
Injection site lumps / bruising: when accidentally injected SubQ at volume; resolves in days, fix by going IM
Route: IM (intramuscular) preferred; IV in clinical settings, SubQ tolerated by some users but stings
Injection site: glute, outer thigh, or deltoid for IM (rotate sites). Avoid SubQ at volumes above 1 ml; it stings and forms lumps
Storage: refrigerated, multi-dose vial typically good 60-90 days after first puncture; already in solution
Notes: Slight sting on injection is normal due to pH and the amino-acid carrier. Inject slowly with a 23-25g needle for IM (1-1.5 inch). The classic bodybuilding protocol times the injection 30-60 minutes before fasted cardio so plasma free carnitine peaks during the workout. No light sensitivity. Do not mix in the same syringe as a GLP-1 or any other compound; separate injections, can be same day.