In 2025, a total of 105 samples identified as anabolic-androgenic steroids were submitted for analysis through the Anabolic Drug Checking program at the Drug Information Center (DIZ) in Zurich.
Anabolic drug checking in Zurich is the world's first opportunity for people who use substances to build muscle to be tested.
The detailed 2025 anabolic steroid analysis can be found in the attached report.
– Testosterone enanthate (20.4%) is most commonly submitted for analysis in liquid form or in ampoules. For tablets, the most common substance is oxandrolone (11.1%)
– About 60% of the substances submitted were correctly labeled, and the declared content matched the analysis results.
– About 40% of the samples were mislabeled. Of these, 14% had a lower (inferior quality) and 4% had a higher active ingredient content than stated. It was notable that, compared to the years 2023–2024, more than twice as many samples (23%) were mislabeled because a different active ingredient was listed. This represents a significant change from the previous year. Furthermore, in 2025, no samples were submitted that contained no active ingredient at all.
– Analysis of the samples tested in the laboratory revealed clear differences between tablets and liquid products such as ampoules. Of the liquid samples, 54 out of 86 were correctly labeled (about 63%). For tablets, this was true of only 8 out of 19 samples (about 42%). Thus, incorrect labeling occurred relatively more frequently with tablets, either because they contained different active ingredients or because the declared active ingredient was present but in significantly different amounts. Despite the higher number of liquid samples, it should be noted that a noticeable proportion of these were also incorrectly labeled. Quality differences can also vary from year to year: While tablets were less frequently mislabeled in 2023/2024, the opposite is true this year.
– The results show that the quality of anabolic steroids can vary significantly depending on the product form and year, with notable variations found in both tablets and liquids/ampoules. This underscores the continued importance of independent testing through drug checking or in a laboratory to understand the risks associated with use.
For more information on anabolic-androgenic steroids, please visit our website here. We now publish a monthly report that provides an overview of mislabeled substances identified through anabolic steroid drug testing at the Drug Information Center (DIZ) in Zurich.
The results published here are not representative of the substance market in the city of Zurich or Switzerland.
