We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more
Clt6.5
Carnitine L-Tartrate Research
Likely helpsHigh safety
22 peer-reviewed studies
What the evidence says
Likely helps
Carnitine L-Tartrate appears to help in 3 of 3 studies with measurable effects — the evidence leans clearly favourable.
Most evidence is from high-quality meta-analyses and randomised trials published 2002–2025 with a typical study size of 20 participants.
Based on 22 studies · 2 meta-analyses · 17 RCTs · 1,990 total participants
Confidence
High
What the studies found
3helped· 19 more without graded effect data
By outcome
RecoveryReduced muscle soreness and faster recovery · Acute and 2-3 weeks
2Exercise performance at moderate and high intensitySystematic ReviewCited 19×2021
However, chronic or acute l-C or GPL-C supplementation did not present improvements on moderate exercise performance.
Mielgo-Ayuso J et al. · Nutrients (2021)
The main aim of the present systematic review was to determine the effects of oral l-C supplementation on moderate- (50-79% V˙O2 max) and high-intensity (≥80% V˙O2 max) exercise performance and to show the effective doses and ideal timing of its intake.
Out of those, three measured the effect of an acute supplementation, and three described the effect of a chronic supplementation, but no significant improvements on performance were found.
On the other hand, the effects of l-C supplementation on moderate exercise performance variables were observed in six studies.
These findings agree with previous observations among healthy adult subjects and demonstrate that L-carnitine tartrate supplementation beyond 35 days is beneficial for improving recovery and reducing fatigue following exercise across gender and age.
Stefan M et al. · Nutrients (2021)
Compared to placebo, L-carnitine tartrate supplementation was able to improve perceived recovery and soreness (p = 0.021), and lower serum creatine kinase (p = 0.016).
These findings agree with previous observations among healthy adult subjects and demonstrate that L-carnitine tartrate supplementation beyond 35 days is beneficial for improving recovery and reducing fatigue following exercise across gender and age.
Positive and negative aspects of l-carnitine supplementation need to be clarified.
Sawicka AK et al. · Nutrients (2018)
A marked increase in free plasma carnitine concentration was observed due to l-carnitine supplementation.
No substantial changes in other parameters were noted.
In the current study, supplementation for 24 weeks affected neither the skeletal muscle strength nor circulating markers in healthy women over 65 years of age.
In conclusion, ingesting a multi-ingredient supplement before, during, and immediately after a 90-min intermittent sprint test resulted in no effects on performance and fatigue while the accumulation of some biomarkers of muscle damage could be attenuated.
Naclerio F et al. · Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme (2014)
Creatine kinase at 24h was lower (p < 0.05) in the multi-ingredient (461.8 ± 271.8 U·L) compared with both carbohydrate and placebo (606 ± 314.5 U·L and 636 ± 344.6 U·L, respectively).
Interleukin-6 increased at both post and 1h compared with pre (p < 0.05) with no differences between conditions.
In conclusion, ingesting a multi-ingredient supplement before, during, and immediately after a 90-min intermittent sprint test resulted in no effects on performance and fatigue while the accumulation of some biomarkers of muscle damage could be attenuated.
These responses suggest that LC may induce subtle changes in substrate handling in metabolically active tissues when fatty-acid availability is increased, but it does not affect whole-body substrate utilization during short-duration exercise at the intensities studied.
Broad EM et al. · International journal of sport nutrition and exercise metabolism (2011)
Fifteen endurance-trained male athletes undertook exercise trials after a 2-d high-carbohydrate diet (60% CHO, 25% fat) at baseline (D0), on Day 14 (D14), and after a single day of high fat intake (15% CHO, 70% fat) on Day 15 (D15) in a double-blind, placebo-controlled, pair-matched design.
Exercise trials consisted of 80 min of continuous cycling comprising 20-min periods at each of 20%, 40%, 60%, and 80% VO2peak.
During the D15 trial, heart rate (p < .05 for 20%, 40%, and 60% workloads) and blood glucose concentration (p < .05 for 40% and 60% workloads) were lower during exercise in the LC group than in P.
11Flow-mediated dilation after high-fat mealRCTCited 25×n=30 · small study2008
In conclusion, consistent with other work showing a beneficial effect of carnitine on vascular function, these findings indicate that carnitine supplementation in healthy individuals improves postprandial FMD after a high-fat meal.
Volek JS et al. · The American journal of cardiology (2008)
Noticeable benefit
← WorseNo effectBetter →
Likely real
Thirty men and women (age 30 +/- 8 year, body mass 72.9 +/- 17.1 kg, body fat 13.0 +/- 6.4%) participated in 2 vascular testing days, each preceded by 3 weeks of supplementation with either 2 g/day of L-Carnitine (L-Carnitine L-Tartrate) or placebo with a 3- to 5-week washout period between trials.
After 3 weeks of supplementation, peak FMD in the fasting state was similar between the carnitine and placebo trials, averaging 6.6%.
Peak FMD during the postprandial period decreased to 5.8% at 1.5 hours during placebo and increased to 7.7% during the carnitine trial (n = 30: p = 0.043 for supplement by time interaction effect).
In summary, these data demonstrated that: 1) feeding after RE increased AR content, which may result in increased testosterone uptake, and thus enhanced luteinizing hormone secretion via feedback mechanisms; and 2) LCLT supplementation upregulated AR content, which may promote recovery from RE.
Kraemer WJ et al. · Medicine and science in sports and exercise (2006)
Post-RE feeding significantly increased AR content compared with baseline and water trials for both LCLT and PL.
In summary, these data demonstrated that: 1) feeding after RE increased AR content, which may result in increased testosterone uptake, and thus enhanced luteinizing hormone secretion via feedback mechanisms; and 2) LCLT supplementation upregulated AR content, which may promote recovery from RE.
14Biochemical markers of recovery from physical exertionRCTCited 17×n=9 · very small study2010
After 3 weeks of each supplementation protocol, each participant then performed an acute resistance exercise challenge of 4 sets of 15 repetitions of squat/leg press at 50% 1-repetition maximum and...
Ho JY et al. · Metabolism: clinical and experimental (2010)
After 3 weeks of each supplementation protocol, each participant then performed an acute resistance exercise challenge of 4 sets of 15 repetitions of squat/leg press at 50% 1-repetition maximum and continued supplementation over the recovery period that was evaluated.
However, markers of physical performance (ie, strength, power, get up and go) were not affected by supplementation.
These findings support our previous findings of l-carnitine in younger people that such supplementation can reduce chemical damage to tissues after exercise and optimize the processes of muscle tissue repair and remodeling.
15Plasma carnitine concentrations during pregnancyRCTCited 29×n=26 · very small study2009
This study confirms that plasma carnitine concentrations decline in the course of pregnancy, an effect that can be prevented by the supplementation of carnitine.
Keller U et al. · European journal of clinical nutrition (2009)
This study confirms that plasma carnitine concentrations decline in the course of pregnancy, an effect that can be prevented by the supplementation of carnitine.
16Carbohydrate, protein, and fat metabolism during exerciseRCTCited 19×n=20 · very small study2008
The tendency toward suppressed ammonia accumulation, however, indicates that oral LC supplementation might have the potential to reduce the metabolic stress of exercise or alter ammonia production or removal, which warrants further investigation.
Broad EM et al. · International journal of sport nutrition and exercise metabolism (2008)
Participants exercised for 90 min at 70% VO2max after 2 days of a prescribed diet (M +/- SD: 13.6 +/- 1.6 MJ, 57% carbohydrate, 15% protein, 26% fat, 2% alcohol) before and after supplementation.
Results indicated no change in carbohydrate oxidation, nitrogen excretion, branched-chain amino acid oxidation, or plasma urea during exercise between the beginning and end of supplementation in either group.
After 2 wk of LC supplementation the plasma ammonia response to exercise tended to be suppressed (0 vs. 2 wk at 60 min exercise, 97 +/- 26 vs. 80 +/- 9, and 90 min exercise, 116 +/- 47 vs. 87 +/- 25 micromol/L), with no change in the placebo group.
17Metabolic stress markers and muscle damage after exerciseRCTCited 29×n=8 · very small study2007
Use of LCLT appears to attenuate metabolic stress and the hypoxic chain of events leading to muscle damage after exercise.
Spiering BA et al. · Journal of strength and conditioning research (2007)
Serum carnitine concentrations increased (p < or = 0.05) following the 1 g and 2 g doses, with the 2-g dose providing the highest carnitine concentrations.
The 1- and 2-g doses reduced postexercise serum hypoxanthine, serum xanthine oxidase, serum myoglobin, and perceived muscle soreness.
In conclusion, both the 1- and 2-g doses were effective in mediating various markers of metabolic stress and of muscle soreness.
Four weeks LCLT supplementation had no effect on substrate utilization or endurance performance.
Broad EM et al. · International journal of sport nutrition and exercise metabolism (2005)
In a randomized, placebo-controlled, double-blind crossover design, 15 trained males undertook exercise trials during two 4 wk supplementation periods, with either 3 g L-Carnitine L-tartrate (LCLT) or 3 g placebo (P) daily.
Subsequent 20 km time trial duration was shorter after P (P0 31:29 +/- 3:50, P4W 29:55 +/- 2:58 min:s, P < 0.01), with no significant change over LCLT (LCLT0 31:46 +/- 4:06, LCLT4W 31.19 +/- 4.08 min:s).
Four weeks LCLT supplementation had no effect on substrate utilization or endurance performance.
Under these experimental conditions, chronic LCLT supplementation increased CHO oxidation in males during exercise but this was not observed in females.
Abramowicz WN et al. · International journal of sport nutrition and exercise metabolism (2005)
Twelve healthy active subjects (6 male, 6 female) performed 60 min of exercise (60% VO(2max)) on 3 occasions after supplementing with L-Carnitine L-tartrate (LCLT) or placebo.
In females, no difference in rate of, or total, CHO oxidation was observed between trials.
No effects on fat oxidation or hematological responses were noted in either gender group.