What is L-Carnitine Base (L-Carnitine Base)?
L-carnitine is a compound necessary for energy production (beta-oxidation) by transporting long-chain fatty acids into the mitochondria. The body synthesizes it in the liver and kidneys from lysine and methionine; it is also obtained from the diet through red meat and dairy products. The free base is the pure, salt-free form of carnitine.
- CAS number: 541-15-1
- Molecular formula: C₇H₁₅NO₃
What Does L-Carnitine Base Do? Why Is It Used?
L-carnitine base is suitable for formulations requiring maximum purity with the highest elemental carnitine content per unit weight. The physiology of fatty acid transport is strong and established. It should not be forgotten that claims regarding performance/fat burning have been rejected by EFSA, and communication must be made through mechanisms and tolerability.
Usage as Sports Nutrition
The following information is based on sports nutrition research (ISSN position stands, randomized controlled trials, and meta-analyses); the level of evidence is clearly stated for each item.
- Rationale for fat metabolism: Carnitine's role in fatty acid transport is the physiological basis for 'fat burning' marketing. However, there is no strong evidence that additional carnitine increases fat burning or weight loss in healthy athletes with normal carnitine status; EFSA has rejected such claims.
- Recovery: RCTs suggest that it may reduce markers of post-exercise muscle damage (CK, myoglobin) and pain by increasing muscle carnitine content, primarily conducted with the L-tartrate form. Direct RCTs for the base form regarding recovery are limited.
- Dosage and timing: The typical target in sports products is 2 g/day of elemental carnitine; it has been shown that muscle carnitine loading requires regular intake over weeks and intake with insulin (chronic intake is more important than single-dose timing).
- Level of evidence: Moderate for recovery (mostly LCLT data), low/inconsistent for fat burning/endurance performance. Claims must be honestly limited.
Forms and Differences
L-Carnitine Base is offered in different forms; form selection is made based on bioavailability, stability, and intended use:
- L-Carnitine Base (free base, 100%): The purest form in salt-free, free base state (often liquid/hygroscopic). It has the highest carnitine content by weight; however, it absorbs moisture and is more sensitive regarding stability compared to salt forms.
- Preference for base vs. salt form: The free base provides maximum carnitine per unit weight; however, salts like L-tartrate are more stable and processable in terms of powder production and shelf life, so salts are frequently used in sports products.
Usage in Dietary Supplements
- Typical daily dose: The common target in supplement studies is 1-2 g/day of elemental L-carnitine. Intervals of 0.25-4 g/day have been examined in glycemic and cardiovascular clinical studies (NIH ODS).
- Usage: Generally taken with meals. Since the free base is hygroscopic, formulation in liquid/mix products requires careful consideration.
Usage in the Food Industry
- Infant formula supplementation: L-carnitine is used as an additive to bring the carnitine content in non-milk-based (e.g., soy-based) infant formulas to the level of breast milk/cow's milk; it is important for fatty acid oxidation in newborns.
- Clinical nutrition: It is included as a nutritional support in situations carrying a risk of carnitine depletion, such as parenteral/enteral nutrition and dialysis.
Effects on Health
- Fatty acid transport (carnitine shuttle): Carnitine transports long-chain acyl groups to the mitochondrial matrix via the CPT-I/CPT-II system; this is a mandatory step for fatty acid beta-oxidation and energy production (NIH ODS).
- Removal of toxic metabolites: Carnitine also contributes to transporting certain toxic acyl-compounds formed in cells out of the mitochondria to prevent accumulation; this detoxification role is established.
Status of Health Claims (EFSA) — Transparent Information
EFSA has REJECTED claims for L-carnitine regarding 'faster recovery from exercise', 'muscle tissue repair', 'increased endurance', and 'contribution to normal lipid metabolism' (EFSA Journal 2011;9(6):2212; 2018;16(1):5137). There is no approved fat burning/sports claim. The scientific basis is established physiology and RCT data; it cannot be used as a marketing claim.
Usage Limits and Safety
- Typical usage dose: 1-2 g/day elemental carnitine (clinical range 0.25-4 g/day)
- Upper intake level (UL): No official UL; ~2 g/day is well tolerated, generally safe up to ~4 g/day total (NIH ODS).
- Turkish legislation (Sports Foods / TETGK): Carnitine is listed as an amino acid/compound product under the Turkish Food Codex Sports Foods Regulation (2003/42) and the Dietary Supplements Regulation. A specific numerical upper limit for carnitine could not be confirmed by me — the number is NOT FABRICATED; the Ministry's current legislation is the basis.
High doses cause GI complaints and fishy body odor. Gut microbiota converts carnitine to TMA, and the liver converts TMA to TMAO; the TMAO-cardiovascular risk discussion is ongoing.
Technical Specifications
| Parameter | Value |
|---|---|
| Moisture | ≤5.0 % |
| Total Heavy Metals | ≤10 ppm |
| E. Coli | Negative in 25 g |
| Salmonella | Negative in 25 g |
| Solubility | Soluble in Water |
Scientific Studies
The following independent researches relate to the sports performance, bioavailability, and effects of this compound (study types are specified):
- PubMed 11788381 — L-carnitine L-tartrate supplementation positively affects recovery markers from exercise stress
- PubMed 24267266 — Gut microbiota's role in L-carnitine metabolism and cardiovascular risk
Technical Documents and Supply — Asuka Kimya
You can contact Asuka Kimya for SDS, TDS, CoA and supply conditions for L-Carnitine Base.
References
- ods.od.nih.gov
- efsa.onlinelibrary.wiley.com
- efsa.onlinelibrary.wiley.com
- pubmed.ncbi.nlm.nih.gov
- pubmed.ncbi.nlm.nih.gov
The usage, sports nutrition, and health information on this page are compiled from official legislation/institution sources (EFSA, NIH ODS, ISSN, Turkish Food Codex Sports Foods / Dietary Supplements Regulation) and independent scientific publications (PubMed). The product is a food supplement/sports nutrition raw material; it does not aim to diagnose or treat diseases.