Chemical and physical manipulation

Examples of chemical and physical tampering include the substitution and/or adulteration of urine. Photo: iStock.com/tadamichi

According to the World Anti-Doping Agency (WADA) Prohibited List, the manipulation of urine samples is listed under M2 (as of January 1, 2026).
 
M2. Chemical and physical manipulation

The following methods are prohibited:

  1. The actual or attempted unauthorized interference to alter the integrity and validity of samples collected during doping controls. This includes, among other things, the substitution and/or adulteration (e.g., with proteases) of urine.
  2. Intravenous infusions and/or injections of more than 50 ml within a six-hour period, unless they are lawfully administered in the course of hospital admissions or clinical examinations.

The exact English text reads as follows:

M2. Chemical and Physical Manipulation

  1. Tampering, or attempting to tamper, to alter the integrity and validity of samples collected during doping control. Including, but not limited to: sample substitution and/or adulteration, e.g., addition of proteases to the sample.
  2. Intravenous infusions and/or injections of more than a total of 100 mL per 12-hour period, except for those legitimately received in the course of hospital treatments, surgical procedures, or clinical diagnostic investigations.
     

Historical Perspective

As of 2008

Manipulation: Chemical and physical manipulations
The World Anti-Doping Agency (WADA) amended the regulations regarding this prohibited method (see below) such that, in addition to the manipulation of a urine sample, as stated in point 1 of the English text, intravenous infusions are also prohibited (point 2) if they are not medically justified.

Regarding this provision, attending physicians have raised questions about where exactly the line is drawn between a permitted medical indication and a prohibited measure. WADA therefore included the following addition in the 2008 Prohibited List for the first time: Infusions are permitted only in acute medical situations, and a subsequent Therapeutic Use Exemption (TUE) is required.

Clarification regarding the TUE procedures for intravenous infusions can only be provided by the respective responsible anti-doping organizations, e.g., in Germany, the National Anti-Doping Agency (NADA) in Bonn.

The exact text of the 2008 WADA Prohibited List reads:

M2. Chemical and Physical Manipulation

  1. Tampering, or attempting to tamper, in order to alter the integrity and validity of Samples collected during Doping Controls is prohibited. These
    include but are not limited to catheterization, urine substitution, and/or alteration.
  2. Intravenous infusion is prohibited. In an acute medical situation where this method is deemed necessary, a retroactive Therapeutic Use Exemption will be required.

German translation (Federal Law Gazette, 2008, Part II, No. 8, issued in Bonn on April 21, 2008):

M2. Chemical and physical manipulation

  1. It is prohibited to actually or attempt to improperly influence the integrity and validity of samples taken during doping controls. This includes, among other things, catheterization, the substitution, and/or the alteration of urine.
  2. Intravenous infusion is prohibited. In an acute medical situation where this method is deemed necessary, a retroactive therapeutic use exemption is required.

As of February 6, 2003

Pharmacological, chemical, and physical manipulation of a urine sample

"The IOC Medical Commission prohibits the use of substances and methods that affect the integrity and validity of urine samples, e.g., catheterization, urine substitution, dilution of urine, suppression of renal elimination by drugs (e.g., by probenecid and related compounds), and the administration of epitestosterone*.

*However, since January 1, 2003, epitestosterone has been listed under Group I Prohibited Substances / Masking Agents.

In recent years, there have been repeated reports of urine sample tampering during doping controls. Replacing urine in the bladder via a catheter before arriving at the doping control station, providing urine from bottles or plastic containers brought along, and diluting urine during the collection procedure when unattended were actions that, if discovered, resulted in immediate disqualification.

The rules did not prohibit such measures to tamper with urine samples with the necessary legal clarity.

The detection of Probenecid**, a pharmacological manipulation, prompted the IOC Medical Commission in 1987 to ban manipulations during urine collection. This is intended to ensure that an unadulterated urine sample from the tested athlete is available for doping analysis." (from Donike and Rauth, 1996)

**Since January 1, 2003, however, probenecid has been listed under Group I: Prohibited Substances / Masking Agents