Changing in Plasma Concentration of a New Form of Creatine

NCT07838805 | Not Yet Recruiting

• 1 other identifier: CREATINE
• Study Type: interventional
• Target: 9
• Locations: 1 country
• Sites: 1

Brief Summary

Creatine is one of the most popular supplements among athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations, improving exercise performance and/or enhancing training adaptations. Research has also indicated that creatine supplementation may improve post-exercise recovery and may help with injury prevention, thermoregulation, rehabilitation, and neuroprotection in cases of concussion and/or spinal cord injury. Several clinical applications of creatine supplementation have also been investigated, particularly in relation to neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's disease, and Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, cerebral and cardiac ischemia, adolescent depression, and pregnancy. The most commonly studied form of creatine in the literature is creatine monohydrate. The uptake of creatine first involves its absorption into the bloodstream and subsequently its uptake by target tissues. Plasma creatine levels typically peak about 60 minutes after the oral ingestion of creatine monohydrate. An initial increase in plasma creatine levels, followed by a reduction, can indirectly suggest increased creatine uptake by target tissues. However, in recent years, new formulations of creatine have been developed to improve its solubility, stability, or bioavailability. Therefore, it is of interest to evaluate whether these formulations differ in absorption kinetics from creatine monohydrate, the reference form in the literature. The aim is to compare the blood absorption of a new formulation of creatine (containing Creatine Phosphate, Creatine Pyruvate, Creatine Hydrochloride) with that of traditional creatine monohydrate. It is hypothesized that the new formulation has a pharmacokinetic profile similar to that of creatine monohydrate.

Conditions

Creatine

Keywords

creatine

Outcome Measures

Primary Outcomes (1)

• Total plasma creatine concentration

  Total plasma creatine concentration will be determined using a commercially available enzymatic assay kit (Creatine Assay Kit, Abcam, ab65339), according to the manufacturer's instructions. The assay is based on an enzymatic reaction that converts creatine (and phosphocreatine) into a detectable product, generating a colorimetric signal proportional to creatine concentration. Absorbance will be measured spectrophotometrically at the recommended wavelength. A standard calibration curve will be generated using creatine standards provided with the kit, and sample concentrations will be calculated by interpolation. All plasma samples will be analyzed in duplicate, and quality control samples will be included to ensure assay reliability. Although the assay measures total creatine, the contribution of phosphocreatine in plasma is considered negligible; therefore, measured values will primarily reflect circulating free creatine.

  Blood samples for plasma analysis will be collected at six specific timepoints: baseline (T0) and at 30 (T1), 60 (T2), 90 (T3), 120 (T4), and 180 (T5) minutes following creatine administration.

Study Arms (2)

New formulation of creatine (Creamix) group

EXPERIMENTAL

Supplemented participants will receive 10g of new formulation of creatine dissolved in 200 mL of water

Dietary Supplement: New Formulation of Creatine (Creamix)

Creatine Monohydrate group

ACTIVE COMPARATOR

Supplemented participants will receive 5g of creatine monohydrate dissolved in 200 mL of water

Dietary Supplement: Active Comparator: Creatine Monohydrate

Interventions

New Formulation of Creatine (Creamix) DIETARY_SUPPLEMENT

Participants will arrive at the laboratory after an overnight fast (8-10 h), having consumed their last meal no later than 20:00 h on the previous day. Participants will be asked to refrain from creatine supplementation for at least 2-4 weeks prior to the experimental session. During the entire experimental session, no food, caffeine or caloric beverages will be allowed. Water intake will be standardized within predefined limits (250 mL prior to baseline and up to 500 mL during the session). Creamix (10g) will be administered dissolved in water, and no additional fluids will be allowed for at least 20 min following ingestion to minimize variability in gastrointestinal absorption. The exact time of ingestion will be recorded and defined as time zero (T0). Blood samples for plasma analysis will be collected at baseline and at 30, 60, 90, 120, and 180 minutes following creatine administration, in accordance with previously published protocols (Jäger et al., 2007; Harris et al., 2004).

New formulation of creatine (Creamix) group

Active Comparator: Creatine Monohydrate DIETARY_SUPPLEMENT

Participants will arrive at the laboratory after an overnight fast (8-10 h), having consumed their last meal no later than 20:00 h on the previous day. Participants will be asked to refrain from creatine supplementation for at least 2-4 weeks prior to the experimental session. During the entire experimental session, no food, caffeine or caloric beverages will be allowed. Water intake will be standardized within predefined limits (250 mL prior to baseline and up to 500 mL during the session). Creatine (5g) will be administered dissolved in water, and no additional fluids will be allowed for at least 20 min following ingestion to minimize variability in gastrointestinal absorption. The exact time of ingestion will be recorded and defined as time zero (T0). Blood samples for plasma analysis will be collected at baseline and at 30, 60, 90, 120, and 180 minutes following creatine administration, in accordance with previously published protocols (Jäger et al., 2007; Harris et al., 2004).

Creatine Monohydrate group

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age between 18 and 35 years
• No creatine supplementation in the previous 6 months
• No history of cardiovascular, metabolic, muscular, or neurological diseases
• BMI: 18-30 kg/m²

You may not qualify if:

• Use of medications or supplements that may affect muscle metabolism or creatine absorption.

Sponsors & Collaborators

• University of Padova: lead

Study Sites (1)

Department of Biomedical Sciences, University of Padua

Padova, PD, 10034, Italy

Location

Study Officials

• Antonio Paoli

  University of Padua Department of Biomedical Sciences

  STUDY DIRECTOR

Central Study Contacts

Antonio Paoli

CONTACT

0498275318; antonio.paoli@unipd.it

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 18, 2026
• First Posted: September 24, 2026
• Study Start: September 17, 2026
• Primary Completion (Estimated): October 17, 2026
• Study Completion (Estimated): November 1, 2026
• Last Updated: September 24, 2026

Record last verified: 2026-09

Locations

IT (1)