Peptides MetabolicWeight Loss Human clinical data

L-Carnitine (Injectable)

Levocarnitine · Carnitine

14.4 hours

Half-life

50–500 mg

Typical dose

Ongoing for deficiency; 4–12 weeks in community fat-loss runs

Cycle length

Amino-acid-derived compound involved in fatty-acid transport; injectable form used in "Lipo" mixes.

Key takeaways

Approved drug (levocarnitine) for carnitine deficiency; off-label injectable use is the wellness market.
Meta-analyses show modest weight-loss effects, roughly 1.3 kg over placebo.
Estimated half-life about 14 hours injected; oral bioavailability is poor, under 20%.
High doses can cause fishy body odor and GI upset; long-term TMAO concerns are debated.

🚧 Expanded guide coming soon. This compound has PK data and a source — a full overview, mechanism, and dosing guide is pending editorial review.

Reported dosing protocols

Protocols reported in research literature and clinic/community use — informational context, not a dosing recommendation.

Use case	Dose	Route	Frequency	Duration
Carnitine deficiency (label)	50–100 mg/kg/day (max 3 g/day oral)	Oral or IV	Divided 2–3× daily	Chronic
Fat loss / performance (community)	200–500 mg	IM or SubQ	Once daily	4–12 weeks reported

Pharmacokinetic summary

Model tier: Simple (t½ + F, Tmax estimated)
Half-life: 14.4 hours
Bioavailability: 70%
Typical dose: 50–500 mg

Frequently asked questions

Does injectable L-carnitine burn fat?

Not meaningfully in people with normal carnitine status. Meta-analyses of randomized trials find about 1.3 kg extra weight loss versus placebo, and performance benefits are inconsistent. Injections raise blood levels far more than oral, but that hasn't translated into strong outcomes.

Why inject instead of taking capsules?

Oral carnitine absorbs poorly, under 20% bioavailability, so injection raises plasma levels much more. Whether that matters clinically is another question; most positive trial results come from deficient or older populations.

Is L-carnitine safe long-term?

At label doses for deficiency, yes; GI upset and fishy body odor are the common complaints. Gut bacteria convert carnitine to TMAO, which observational studies link to cardiovascular risk, but whether supplemental doses meaningfully raise that risk is unresolved.

References

Estimated — Quaternary ammonium compound; IV half-life ~hours.
Obes Rev 2016 — (L-)carnitine and weight loss: systematic review and meta-analysis — Meta-analysis of randomized trials: roughly 1.3 kg additional weight loss versus placebo.
DailyMed — Levocarnitine injection (label) — Approved indication and dosing for carnitine deficiency.

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