title: A multi-ingredient, pre-workout supplement is apparently safe in healthy males and females.
abstract: BACKGROUND
  Pre-workout supplements (PWS) have become increasingly popular with recreational and competitive athletes. While many ingredients used in PWS have had their safety assessed, the interactions when combined are less understood.
  
  
  OBJECTIVE
  The purpose of this study was to examine the safety of 1 and 2 servings of a PWS.
  
  
  METHODS
  Forty-four males and females (24.4±4.6 years; 174.7±9.3 cm; 78.9±18.6 kg) from two laboratories participated in this study. Subjects were randomly assigned to consume either one serving (G1; n=14) or two servings (G2; n=18) of PWS or serve as an unsupplemented control (CRL; n=12). Blood draws for safety panels were conducted by a trained phlebotomist before and after the supplementation period.
  
  
  RESULTS
  Pooled data from both laboratories revealed significant group×time interactions (p<0.05) for mean corpuscular hemoglobin (MCH; CRL: 30.9±0.8-31.0±0.9 pg; G1: 30.7±1.1-30.2±0.7 pg; G2: 30.9±1.2-30.9±1.1 pg), MCH concentration (CRL: 34.0±0.9-34.4±0.7 g/dL; G1: 34.1±0.9-33.8±0.6 g/dL; G2: 34.0±1.0-33.8±0.8 g/dL), platelets (CRL: 261.9±45.7-255.2±41.2×10(3)/µL; G1: 223.8±47.7-238.7±49.6×10(3)/µL; G2: 239.1±28.3-230.8±34.5×10(3)/µL), serum glucose (CRL: 84.1±5.2-83.3±5.8 mg/dL; G1: 86.5±7.9-89.7±5.6 mg/dL; G2: 87.4±7.2-89.9±6.6 mg/dL), sodium (CRL: 137.0±2.7-136.4±2.4 mmol/L; 139.6±1.4-140.0±2.2 mmol/L; G2: 139.0±2.2-138.7±1.7 mmol/L), albumin (CRL: 4.4±0.15-4.4±0.22 g/dL; G1: 4.5±0.19-4.5±0.13 g/dL; G2: 4.6±0.28-4.3±0.13 g/dL), and albumin:globulin (CRL: 1.8±0.30-1.8±0.28; G1: 1.9±0.30-2.0±0.31; G2: 1.8±0.34-1.8±0.34). Each of these variables remained within the clinical reference ranges.
  
  
  CONCLUSIONS
  The PWS appears to be safe for heart, liver, and kidney function in both one-serving and two-serving doses when consumed daily for 28 days. Despite the changes observed for select variables, no variable reached clinical significance.
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.
authors.forename: Jordan M
authors.initials: JM
authors.lastname: Joy
authors.affiliation: Health Science and Human Performance Department, University of Tampa, Tampa, FL, USA.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Lowery
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Falcone
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.
authors.forename: Roxanne M
authors.initials: RM
authors.lastname: Vogel
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.
authors.forename: Matt M
authors.initials: MM
authors.lastname: Mosman
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.
authors.forename: Chih-Yin
authors.initials: CY
authors.lastname: Tai
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.
authors.forename: Laura R
authors.initials: LR
authors.lastname: Carson
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.|Human Performance and Sport, Metropolitan State University of Denver, Denver, CO, USA.
authors.forename: Dylan
authors.initials: D
authors.lastname: Kimber
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.|Human Performance and Sport, Metropolitan State University of Denver, Denver, CO, USA.
authors.forename: David
authors.initials: D
authors.lastname: Choate
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Kim
authors.affiliation: Health Science and Human Performance Department, University of Tampa, Tampa, FL, USA.
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Wilson
authors.affiliation: MusclePharm Sports Science Institute, MusclePharm Corp., Denver, CO, USA.|Department of Sports Exercise Science, United States Sports Academy, Daphne, AL, USA; jordan@musclepharm.com.
authors.forename: Jordan R
authors.initials: JR
authors.lastname: Moon
keywords: caffeine; hematology; nitrates; sports supplement; toxicity