Endpoint

Serum creatine kinase activity

A transferase that catalyzes formation of phosphocreatine from ATP + creatine. The reaction stores ATP energy as phosphocreatine. Three cytoplasmic isoenzymes have been identified in human tissues: the MM type from skeletal muscle, the MB type from myocardial tissue and the BB type from nervous tissue as well as a mitochondrial isoenzyme. Macro-creatine kinase refers to creatine kinase complexed with other serum proteins.

Definition from MeSH (D003402), National Library of Medicine, read 2026-09-16. NLM revises MeSH; this copy may not reflect its current record.

CAT:outcome/creatine-kinasereported in U/L9 findings from 9 compounds

Open in the graph

What moved it

How to read these marks

9 findings · 9 compounds · 3 null · by evidence strength

Compound	Direction	Findings	Strongest evidence
Cordyceps militaris	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
L-glutamine	no effect	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
Lactiplantibacillus plantarum	no effect	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
lycopene	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
N-acetyl-L-cysteine	no effect	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
taurine	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
astaxanthin	down	1	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.
creatine	up	1	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.
malic acid	down	1	Evidence strength: insufficient. Mechanistic inference, no evidence found, or evidence weakened below very limited.

Reported to move it

6 findings

taurine — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“Taurine also significantly reduced CK (−39%, 315 ± 10 U/L, p < 0.001) and LDH (−32%, 468 ± 11 U/L, p < 0.001) relative to placebo.”
Quoted verbatim from Practical Nutritional Strategies to Attenuate Physiological Stress in Adolescent Soccer Players: A Comparative Trial of CoQ10 and Taurine..
Study

RCT
Duration

14 days
Dose

4 g/day (eight 500 mg capsules) plus an additional 4 g 90 min before each match simulation on training days
Population

Male under-19 academy soccer players; taurine arm versus placebo arm; value at T2, immediately after the third of three 90-minute soccer match simulations
Practical Nutritional Strategies to Attenuate Physiological Stress in Adolescent Soccer Players: A Comparative Trial of CoQ10 and Taurine.2026PMID:42514298Permalink
Cordyceps militaris — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“Moreover, the creatine kinase level was significantly decreased in the CM group compared with that in the placebo group at 16 weeks after the test food intake (p < 0.05), Table 5).”
Quoted verbatim from Effect of the Administration of Cordyceps militaris Mycelium Extract on Blood Markers for Anemia in Long-Distance Runners..
Study

RCT
Duration

4 months
Dose

1800 mg/day (6 capsules of 300 mg each; 3 morning, 3 evening)
Population

Healthy male long-distance runners during pre-season training; creatine kinase measured at 16 weeks (trial end).
Effect of the Administration of Cordyceps militaris Mycelium Extract on Blood Markers for Anemia in Long-Distance Runners.2024PMID:38931190Industry fundedPermalink
lycopene — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“Furthermore, at post, compared with the HBO group, the CK levels were significantly reduced in the HBO+LYC group (p < 0.05) (Table S3).”
Quoted verbatim from Effects of Hyperbaric Oxygen Combined with Lycopene on Oxidative Stress and Inflammation in Collegiate Badminton Players After High-Intensity Training..
Study

RCT
Duration

4 weeks
Dose

15 mg lycopene daily (three 5 mg softgels with dinner)
Population

Collegiate badminton players after high-intensity training; hyperbaric oxygen plus lycopene capsules versus hyperbaric oxygen plus placebo capsules (hyperbaric oxygen given to both arms); post-intervention timepoint
Effects of Hyperbaric Oxygen Combined with Lycopene on Oxidative Stress and Inflammation in Collegiate Badminton Players After High-Intensity Training.2026PMID:42739033Industry fundedPermalink
creatine — increases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Finding
“CAERS report 2018-CFS-000217: Blood creatine phosphokinase increased following CON-CRET.”
Quoted verbatim from openFDA CAERS report 2018-CFS-000217.
Study

spontaneous report · not in humans
Population

not applicable — single spontaneous report, no defined population (age 29 year(s), Male)
openFDA CAERS report 2018-CFS-000217CAERS:2018-CFS-000217Permalink
astaxanthin — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Finding
“Similarly, administration of ASX decreased the CK levels in swimming training mice.”
Quoted verbatim from High-Dose Astaxanthin Supplementation Suppresses Antioxidant Enzyme Activity during Moderate-Intensity Swimming Training in Mice..
Study

animal · not in humans
Duration

4 weeks
Dose

5, 15 or 30 mg/kg body weight daily by oral gavage in olive oil, two hours before swimming
Population

Male C57BL/6 mice (n = 8 per group) given moderate-intensity swimming training for four weeks; ASX at 5, 15 and 30 mg/kg BW by gavage in olive oil versus swimming controls given olive oil; plasma CK
High-Dose Astaxanthin Supplementation Suppresses Antioxidant Enzyme Activity during Moderate-Intensity Swimming Training in Mice.2019PMID:31159211Permalink
malic acid — decreases
InsufficientEvidence strength: insufficient. Mechanistic inference, no evidence found, or evidence weakened below very limited.Finding
“However, the levels of CK were significantly decreased in the L-malate-treated groups.”
Quoted verbatim from Effects of L-malate on physical stamina and activities of enzymes related to the malate-aspartate shuttle in liver of mice..
Study

animal · not in humans
Duration

4 weeks
Dose

0.210 g/kg and 0.630 g/kg L-malate once daily by feeding needle
Population

Mice given L-malate orally for 30 days, compared with control group, assessed after forced swimming
Effects of L-malate on physical stamina and activities of enzymes related to the malate-aspartate shuttle in liver of mice.2007PMID:16555951Permalink

Measured, no effect detected

3 findings

Lactiplantibacillus plantarum — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull result
“There were no significant differences in glucose and creatine kinase levels between the Control and TWK10‐HK groups at each collection time point.”
Quoted verbatim from Effects of heat-killed Lactiplantibacillus plantarum TWK10 on exercise performance, fatigue, and muscle growth in healthy male adults..
Study

RCT
Duration

6 weeks
Dose

3 × 10^10 heat-killed cells/day (two 1.5 × 10^10 capsules) after meals
Population

Healthy untrained males aged 20-40 years; serum sampled during and after a 30-min fixed-intensity exercise challenge at 60% VO2max
Effects of heat-killed Lactiplantibacillus plantarum TWK10 on exercise performance, fatigue, and muscle growth in healthy male adults.2023PMID:37816697Industry fundedPermalink
N-acetyl-L-cysteine — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull result
“However, we saw no significant effect of NAC on TNF-α, CK or GSSG concentrations.”
Quoted verbatim from The impact of N-acetylcysteine on lactate, biomarkers of oxidative stress, immune response, and muscle damage: A systematic review and meta-analysis..
Study

meta-analysis
Population

Participants in pooled studies of NAC supplementation, concentrations after physical exertion
The impact of N-acetylcysteine on lactate, biomarkers of oxidative stress, immune response, and muscle damage: A systematic review and meta-analysis.2024PMID:39632267Permalink
L-glutamine — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull result
“Consistent with muscle mass, markers of myofibrillar protein breakdown (3 methyl-histidine/creatinine ratio in urine) and serum CPK were not affected by Gln treatment compared with placebo (Table 2).”
Quoted verbatim from Lack of functional benefit with glutamine versus placebo in Duchenne muscular dystrophy: a randomized crossover trial..
Study

crossover
Dose

0.5 g/kg/d oral glutamine once daily for 4 months versus maltodextrin placebo of equal weight, 1-month washout
Population

30 ambulant boys aged 2 to 10 years with Duchenne muscular dystrophy, 5 on corticosteroids; change over the 4-month glutamine phase versus the 4-month placebo phase
Lack of functional benefit with glutamine versus placebo in Duchenne muscular dystrophy: a randomized crossover trial.2009PMID:19421321Permalink

How it is measured

Serum creatine kinase (CK) activity by clinical assay, used as a marker of exercise-induced muscle damage. Time since the damaging bout recorded with each finding.