Carnitine L-Tartrate Research
21 peer-reviewed studies · Evidence score: 6.5/10
L-Carnitine supplementation for recovery after exercise: A systematic review and meta-analysis of randomized controlled trials
Fielding R et al. • Nutrients (2018)
L-Carnitine supplementation significantly reduced exercise-induced muscle damage markers and improved recovery.
- L-Carnitine reduced muscle soreness and serum creatine kinase levels post-exercise
- Recovery was accelerated with supplementation of 1-2 g/day
- L-Carnitine L-Tartrate form showed particular benefit for exercise recovery
Effect of Acute and Chronic Oral l-Carnitine Supplementation on Exercise Performance Based on the Exercise Intensity: A Systematic Review
Mielgo-Ayuso J et al. • Nutrients (2021)
However, chronic or acute l-C or GPL-C supplementation did not present improvements on moderate exercise performance.
- 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.
Evaluation of daily supplementation of fertitonex on different semen parameters in idiopathic male infertility: a randomized double blind placebo controlled cross over study
Elnashar A et al. • International urology and nephrology (2025)
We finally concluded that fertitonex is an effective, tolerable and safe drug that can be used for treating idiopathic male infertility.
- We finally concluded that fertitonex is an effective, tolerable and safe drug that can be used for treating idiopathic male infertility.
- Published in International urology and nephrology (2025)
- Further research warranted to confirm findings
L-Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double-Blind, Placebo-Controlled Trial
Stefan M et al. • Nutrients (2021)
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.
- 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.
- Further research warranted to confirm findings
l-Carnitine Supplementation in Older Women. A Pilot Study on Aging Skeletal Muscle Mass and Function
Sawicka AK et al. • Nutrients (2018)
Positive and negative aspects of l-carnitine supplementation need to be clarified.
- 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.
Effect of a carbohydrate-protein multi-ingredient supplement on intermittent sprint performance and muscle damage in recreational athletes
Naclerio F et al. • Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme (2014)
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.
- 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.
Effects of exercise intensity and altered substrate availability on cardiovascular and metabolic responses to exercise after oral carnitine supplementation in athletes
Broad EM et al. • International journal of sport nutrition and exercise metabolism (2011)
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.
- 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.
Andrological actions of L-carnitine L-tartrate supplementation: Effects on androgen receptor, muscle oxygenation, and hormonal responses
Kraemer WJ et al. • Medicine and Science in Sports and Exercise (2019)
[Small study, n=10] L-Carnitine L-Tartrate supplementation at 2 g/day upregulated androgen receptor content and improved muscle oxygenation during exercise.
- Androgen receptor content in muscle was significantly upregulated after 3 weeks of LCLT
- Muscle tissue oxygenation was improved during resistance exercise
- Hormonal recovery after exercise was enhanced with LCLT supplementation
Carnitine supplementation and exercise performance
Wall BT et al. • Journal of Physiology (2011)
[Small study, n=14] Carnitine increased muscle carnitine and improved exercise performance.
- 20% increase in muscle carnitine
- Improved work output
- Better fuel utilization
Effects of carnitine supplementation on flow-mediated dilation and vascular inflammatory responses to a high-fat meal in healthy young adults
Volek JS et al. • The American journal of cardiology (2008)
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.
- 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).
Androgenic responses to resistance exercise: effects of feeding and L-carnitine
Kraemer WJ et al. • Medicine and science in sports and exercise (2006)
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.
- 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.
- Further research warranted to confirm findings
l-Carnitine l-tartrate supplementation favorably affects biochemical markers of recovery from physical exertion in middle-aged men and women
Ho JY et al. • Metabolism: clinical and experimental (2010)
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- 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.Copyright 2010 Elsevier Inc.
Carnitine status of pregnant women: effect of carnitine supplementation and correlation between iron status and plasma carnitine concentration
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.
- This study confirms that plasma carnitine concentrations decline in the course of pregnancy, an effect that can be prevented by the supplementation of carnitine.
- Published in European journal of clinical nutrition (2009)
- Further research warranted to confirm findings
Effects of L-carnitine L-tartrate supplementation on muscle oxygenation responses to resistance exercise
Spiering BA et al. • Journal of strength and conditioning research (2008)
Enhanced oxygen consumption would explain why hypoxic stress was attenuated with LCLT supplementation.
- Despite reduced oxygenation, plasma malondealdehyde, a marker of membrane damage, was attenuated during the LCLT trial.
- There were no differences between trials in the vasoactive substance prostacyclin.
- In conclusion, because oxygen delivery was occluded during the forearm protocol, it is proposed that enhanced oxygen consumption mediated the reduced muscle oxygenation during the LCLT trial.
Carbohydrate, protein, and fat metabolism during exercise after oral carnitine supplementation in humans
Broad EM et al. • International journal of sport nutrition and exercise metabolism (2008)
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.
- 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.
Responses of criterion variables to different supplemental doses of L-carnitine L-tartrate
Spiering BA et al. • Journal of strength and conditioning research (2007)
Use of LCLT appears to attenuate metabolic stress and the hypoxic chain of events leading to muscle damage after exercise.
- 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.
Effects of four weeks L-carnitine L-tartrate ingestion on substrate utilization during prolonged exercise
Broad EM et al. • International journal of sport nutrition and exercise metabolism (2005)
Four weeks LCLT supplementation had no effect on substrate utilization or endurance performance.
- 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.
Effects of acute versus chronic L-carnitine L-tartrate supplementation on metabolic responses to steady state exercise in males and females
Abramowicz WN et al. • International journal of sport nutrition and exercise metabolism (2005)
Under these experimental conditions, chronic LCLT supplementation increased CHO oxidation in males during exercise but this was not observed in females.
- 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.
LCLT and androgen receptor content
Kraemer WJ et al. • Medicine & Science in Sports & Exercise (2006)
[Small study, n=10] LCLT supplementation upregulated androgen receptor content.
- Increased AR density
- Enhanced hormonal response
- Better recovery
L-Carnitine L-Tartrate and muscle recovery
Volek JS et al. • American Journal of Physiology (2002)
[Small study, n=10] LCLT reduced markers of metabolic stress and muscle damage.
- Reduced hypoxanthine accumulation
- Attenuated muscle damage
- Improved recovery markers