Responsible use & anti-doping

The Prohibited List and the classes that concern us

Status and revision cycle

The Prohibited List is a mandatory International Standard within the World Anti-Doping Program. It is updated every year after an extensive consultation facilitated by WADA, and each edition takes effect on 1 January — the current edition entered into force on 1 January 2026. A substance's status can therefore change between one January and the next, and a list printed last year is not authority for this year.

S1 — Anabolic agents

Prohibited at all times, both in and out of competition, and all non-Specified Substances. S1.1 covers anabolic androgenic steroids when administered exogenously; S1.2 covers other anabolic agents, among them clenbuterol, osilodrostat, ractopamine, selective androgen receptor modulators (SARMs), zeranol and zilpaterol.

Esters, salts and analogues

S1.1 closes by prohibiting "other substances with a similar chemical structure or similar biological effect(s) including their esters" — the reference to esters was made explicit in the 2026 edition. Esterifying a listed steroid, presenting it as a salt, or altering it into a close structural analogue does not move it outside the class.

Metabolites and markers

Under Article 2.1 of the World Anti-Doping Code, the violation is established by the presence of a prohibited substance, or its metabolites or markers, in an athlete's sample. Clearance of the parent compound is of no help if a characteristic metabolite is still detectable.

S3 — Beta-2 agonists

Prohibited at all times; Specified Substances. All selective and non-selective beta-2 agonists, including all optical isomers, are prohibited — the class covers formoterol, salbutamol, salmeterol, terbutaline, vilanterol, higenamine and others, by every route of administration.

S3 — the inhaled exceptions

The exceptions are narrow, inhaled-only and dose-capped: salbutamol to a maximum of 1600 micrograms over 24 hours in divided doses not exceeding 600 micrograms over 8 hours; formoterol to a maximum delivered dose of 54 micrograms over 24 hours, not exceeding 36 micrograms over 12 hours; salmeterol to a maximum of 200 micrograms over 24 hours, not exceeding 100 micrograms over 8 hours; vilanterol to a maximum of 25 micrograms over 24 hours. Oral and injectable use falls outside the exception entirely.

S3 — urinary thresholds

Salbutamol in urine above 1000 ng/mL, or formoterol above 40 ng/mL, is not consistent with therapeutic use and is reported as an adverse analytical finding, unless the athlete demonstrates through a controlled pharmacokinetic study that the result followed an inhaled therapeutic dose within the limits above. The burden of that demonstration sits with the athlete, after the fact.

S4 — Hormone and metabolic modulators

Prohibited at all times. S4.1 aromatase inhibitors (anastrozole, letrozole, exemestane, formestane, testolactone, aminoglutethimide and related compounds) and S4.2 anti-oestrogenic substances including selective estrogen receptor modulators (clomifene, tamoxifen, raloxifene, toremifene, fulvestrant and others) are Specified Substances; S4.3 agents preventing activin receptor IIB activation and S4.4 metabolic modulators are non-Specified.

Why S4 sits next to S1

Aromatase inhibitors and SERMs have clear oncological and endocrine indications and are legitimate medicines in those settings. They are also taken to offset the endocrine consequences of non-medical androgen use. In sport that is a second, independent prohibition, not an accessory to the first — and in medicine it is a use without diagnosis, monitoring or a prescriber.

Therapeutic Use Exemption (TUE)

A TUE permits an athlete to use a prohibited substance where all four criteria of the International Standard for TUEs are met: a clearly diagnosed medical condition requiring the treatment; no significant enhancement of performance beyond a return to normal health, on the balance of probabilities; no reasonable permitted therapeutic alternative; and the need must not itself arise from prior use, without a TUE, of a substance prohibited at that time. A TUE is granted in advance by the athlete's international federation or national anti-doping organisation, applies to a stated substance, dose and route, and must be renewed. A prescription, a pharmacy label or a supporting letter from a physician is not a TUE.

Detection windows

Oil-solution esters release the parent substance slowly from the injection site, and the longer the ester chain the slower it goes. Parent substances and their metabolites are routinely detectable for weeks, and for the longest esters for many months, after a last dose — long after any subjective effect has passed. No washout interval is reliable, laboratory sensitivity continues to improve, and long-term sample storage means a sample may be reanalysed years later. Ergopharm does not publish clearance estimates and will not answer requests for them.

Strict liability

Article 2.1.1 of the Code places on each athlete the personal duty to ensure that no prohibited substance enters their body. Intent, fault, negligence and knowing use are not required for a violation to be established. Anyone competing under the Code should confirm the current status of every medicine with their own anti-doping organisation, and through a reference service such as Global DRO, before it is taken — not afterwards.

Why non-medical use is not a lesser version of medical use

• Prescription control is not paperwork. It is the mechanism by which a diagnosis is established, an indication is confirmed, a dose is set against the individual, interactions are screened, and treatment is monitored and stopped when it should be. Use outside that framework removes every one of those steps at once.
• Dependence. Androgen use outside medical supervision is associated with a recognised dependence syndrome: escalating dose, continued use despite harm, and a withdrawal state marked by fatigue, loss of libido and depressed mood — a period during which suicidal ideation has been described.
• Cardiovascular harm. Adverse lipid change (suppressed HDL, raised LDL), hypertension, left ventricular hypertrophy and impaired relaxation, polycythaemia with raised haematocrit, and an increased tendency to thrombosis. The pattern accumulates with duration of exposure and is not reliably signalled by how a person feels.
• Hepatic harm. Particularly with 17-alpha-alkylated oral agents: cholestatic jaundice, raised transaminases, peliosis hepatis and hepatic tumours. Parenteral oil solutions avoid the first-pass burden but do not make an androgen hepatically inert.
• Endocrine harm. Suppression of the hypothalamic-pituitary-gonadal axis with reduced endogenous testosterone, testicular atrophy, impaired spermatogenesis and infertility that may take many months to recover and does not always recover fully; gynaecomastia; in women, virilisation with hirsutism, menstrual disturbance, clitoral enlargement and voice deepening that is generally irreversible; in adolescents, premature closure of the epiphyses and permanently reduced adult height.
• Psychiatric effects. Irritability, aggression, hypomanic and manic states during use, and depressed mood on withdrawal. These are effects on the person's judgement, which is precisely the faculty being relied on to manage the use.
• Injection-related harm. Injection-site pain, sterile and infective abscess, cellulitis, nerve injury, intravascular injection and oil embolism, tissue necrosis from incorrect site or technique, and transmission of blood-borne viruses wherever needles, syringes or vials are shared. These risks belong to the act of injection and are independent of what is in the ampoule.
• Product provenance. Substances obtained outside the licensed supply chain have no verifiable identity, strength, sterility or endotoxin control. Serialisation and pack verification exist so that a genuine pack can be distinguished from one that only looks genuine — but they can only be used by someone who obtained the pack through a legitimate route.
• Consequences beyond health. In sport, a violation carries sanction, loss of results and reputational damage. In many jurisdictions, possession or supply of these substances outside a prescription is a criminal matter.