Types

• There are several ways a muscle supplement can cause a positive drug screen. It depends on the type of ingredient in the supplement. Banned ingredients found in muscle building products include: ephedra, stimulants, anabolic derivatives, and other hormone analogues.
  
  

Time Frame

• Depending on the supplement and the sensitivity of the drug screen, it could show up in urine 2-3 weeks after use and in blood 30 days or more after use. Cleansing products can be effective, depending on type to allow you to pass a drug screen.
  
  

Famous Ties

• Many athletes unknowingly take a banned substance and have a positive drug screen. This was the case with tetrahydrogestrinone (THG or "The Clear"). Athletes claimed they were told it was a nutritional supplement when in fact it was an anabolic steroid. So use caution when selecting supplements.
  
  

Considerations

• Carefully read what substances are banned before you take muscle building supplements. Just because the supplement is legal and safe, does not mean it is allowed in your competition or place of employment.
  
  

Expert Insight

• Iowa State University conducted a research study on "Andro," a legal muscle building supplement and found it had deleterious effects to cholesterol levels and did not improve muscle gains.