Peptide & Experimental
Anabolic steroids (anabolics, AAS)
Warning: anabolic-androgenic steroids, doping and health risk · anabolic-androgenic steroids, AAS, anabolics, steroids, roids, testosterone derivatives, trenbolone, stanozolol, metandienone, oxandrolone, oxymetholone
Anabolic-androgenic steroids, anabolics for short, are testosterone and its synthetic derivatives. They build muscle as reliably as hardly any other substance. Precisely for that reason, their cost is by now well measured: heart, hormonal axis and life expectancy.
In short
Anabolic steroids work; this has been established for decades: more muscle mass and more strength, and considerably more with training. Outside of medical therapy, however, they are associated with clearly increased risks. In a large Danish cohort, the users’ risk of death was 2.81 times that of people of the same age, and the risk of heart muscle disease 8.90 times. The body’s own testosterone production is shut down during use and, in some men, does not fully recover even years later. In Germany, trading and passing them on for doping purposes are criminal offenses, as are acquisition and possession of a not insignificant amount, and in sport anabolic steroids are prohibited at all times.
What it is
Anabolic-androgenic steroids, AAS in the scientific literature, are testosterone and molecules derived from it. Anabolic means building up, referring to the effect on muscles and bones. Androgenic means masculinizing, referring to beard growth, a deep voice and libido. The two effects can never be completely separated chemically. The group includes injectable esters such as testosterone enanthate or nandrolone and tablets with a chemically modified structure.
There is legitimate medicine behind it. Testosterone is the standard treatment for genuine, medically proven testosterone deficiency; there is a separate entry on testosterone and TRT. Nandrolone is approved in some EU countries for postmenopausal osteoporosis and for anemia caused by kidney failure; there is a separate entry on that too. This collective entry covers use without a medical indication, that is, in strength sports, bodybuilding and for appearance.
How it works
AAS bind to the androgen receptor in muscle cells and many other tissues. This increases protein synthesis in muscle and the production of red blood cells and changes fat metabolism. At the same time, the brain registers the high hormone level and throttles the signals to the testes. The body’s own testosterone production and sperm production shut down. This is not a side effect that affects only some people, but the direct consequence of the principle of action.
Why people take it
Because it works. A meta-analysis of 187 studies estimates that 3.3 percent of people worldwide have taken AAS at some point in their lives, 6.4 percent of men and 1.6 percent of women. Most users are not competitive athletes but recreational athletes in the gym. Many start only after the age of 20. For the US, researchers estimate 2.9 to 4.0 million people who have used AAS and about 1 million who have developed a dependence in the process.
What is well supported
The effect on muscle is as cleanly established as for few substances in this field. In a randomized trial in the New England Journal of Medicine, 43 healthy men received supraphysiological testosterone or placebo for 10 weeks, each with or without strength training. Even without training, muscle cross-sectional area and strength increased. With training, fat-free mass increased by 6.1 kg, the bench press by 22 kg and the squat by 38 kg. In the prospective HAARLEM study from the Netherlands, 100 percent of the 100 men reported more strength during use. By now, however, the other side is also well established. In the Danish registry cohort with 1,189 users and 59,450 controls, with a mean age of 27.4 years and followed for 11.2 years, 33 users died, compared with 578 among the controls. This amounts to a 2.81-fold increased risk of death. 17 deaths were unnatural, mainly accidents, and 16 natural, mostly from cancer or cardiovascular disease. In the same cohort, the risk of cardiomyopathy was 8.90-fold higher, of heart failure 3.63-fold, of heart attack 3.00-fold, of thrombosis 2.42-fold and of arrhythmias 2.26-fold.
What the studies show
Denmark: mortality and the heart
Men who tested positive in doping controls in Danish gyms between 2006 and 2018, compared with 50 men of the same age from the general population each, via the national registries. After a mean of 11.2 years, mortality was 2.81-fold higher, unnatural deaths 3.64-fold and natural deaths 2.24-fold. A follow-up study found an 8.90-fold risk of heart muscle disease. The study is observational; lifestyle and other substances were not fully recorded.
The heart of long-term users
140 experienced strength athletes between 34 and 54 years of age, 86 of them with at least 2 years of use and 54 without. The ejection fraction of the left ventricle was 52 versus 63 percent in users, the coronary arteries carried more plaque, and the amount of plaque rose with the total duration of use. A Danish PET study with 90 men found impaired blood flow in the smallest heart vessels even in former users, on average 1.5 years after quitting.
The hormonal axis after quitting
37 current and 33 former users and 30 controls. On average 2.5 years after quitting, 27.2 percent of former users were below the lower reference value of 12.1 nmol/l testosterone, compared with none of the controls. 24.2 percent had depressive symptoms, 27.3 percent erectile dysfunction and 40.1 percent reduced libido. A meta-analysis of 32 studies shows that the regulating hormones LH and FSH recover within a year in most cases, but testicular volume and sperm motility suffer.
Where the data stop
The effect is well studied, whereas the long-term consequences of use in the scene have only been studied in observational studies. Randomized trials with the amounts and combinations actually used would be ethically unjustifiable, as the Endocrine Society also writes. The Danish figures concern men who were caught in controls, and women are missing from almost all studies. On cancer risk, the Danish cohort found no increase after 11 years, the incidence ratio was 1.05, but there were only 13 cases among young men. That is no all-clear for the decades that follow. There was also no increased risk of diabetes. In the HAARLEM study, most of the observed effects had receded after 1 year, but it concerned a single phase of use. How many men retain a permanent hormone deficiency has not been cleanly determined; there is not even a uniform definition for it.
Status, approval and legal
Outside of medicine there is no legal route. Individual active substances such as testosterone are prescription-only medicines for clearly defined indications. In § 2, the German Anti-Doping Act prohibits manufacture, trading, dispensing and prescribing for doping purposes, as well as acquisition, possession and import of a not insignificant amount for doping in sport; the limits for each substance are set by the Doping Substances Quantity Ordinance of 2023. Violations under § 4 are punishable by up to 3 years’ imprisonment or a fine, in serious cases, for example when dispensing to persons under 18 or in organized gang trafficking, by 1 to 10 years. Self-doping under § 3 is a criminal offense for elite athletes in the testing pool and for athletes with substantial income. Customs controls imports. The World Anti-Doping Agency lists AAS in the 2026 list under S1.1, prohibited in and out of competition.
Safety
The risks affect several organ systems at the same time. Heart: cardiomyopathy, heart failure, heart attack, thrombosis and arrhythmias are considerably more frequent in the Danish cohort. Hormones: the body’s own production is shut down; after quitting, months of loss of libido and low mood often follow, and in some the deficiency remains. In HAARLEM, every participant had at least one negative effect, most often fluid retention at 56 percent and restlessness at 36 percent, followed by loss of libido in 58 percent, acne in 28 percent and breast gland growth in 19 percent; 4 out of 100 had a serious event, up to and including heart failure and suicidal thoughts. Liver: a particular form of bile stasis, blood-filled cavities in the liver tissue, and benign as well as malignant liver tumors have been described, sometimes with permanent consequences. Women risk partly permanent masculinization. An additional risk is the black market: in a meta-analysis of 19 studies with 5,413 samples, 36 percent were counterfeit and a further 37 percent defective. There is no safe amount outside of medical therapy.
BK-Score Supported, with caveats
| Human evidence | 7 | |
|---|---|---|
| Mechanism | 9 | |
| Safety data | 6 | |
| Hype gap | 4 | |
| Track record of use | 6 |
Evidence 7, because the effect on muscle is established in randomized trials (Bhasin et al. 1996, 43 men, 10 weeks, +6.1 kg fat-free mass with training) and individual active substances are approved for medical indications, but for use without an indication there are only small and short controlled studies. Mechanism 9, because the androgen receptor, protein synthesis and the shutdown of the hormonal axis have been precisely measured in humans. Safety 6, because large registry cohorts with long follow-up are available (Windfeld-Mathiasen et al. 2024 and 2025: 1,189 users versus 59,450 controls, 11.2 years, mortality HR 2.81, cardiomyopathy aHR 8.90), plus prospective data over 1 year (HAARLEM, 100 men) and cross-sectional studies on the heart and hormonal axis, but no randomized long-term data and hardly any data on women. Hype 4, because the effect on muscle is real, but the risks are systematically underestimated in the scene – the Endocrine Society explicitly speaks of a widespread misconception that use is safe or manageable (Pope et al. 2014). Use 6, because testosterone has been used under medical regulation for decades, but non-medical use takes place without supervision in an estimated 3.3 % of the world’s population. Direction mixed: the effect on muscle is undisputed, but for use without a medical indication the data show a clearly increased risk of death and heart disease and lasting hormonal damage in some users (27.2 % below the reference value years after quitting, Rasmussen et al. 2016).
The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)
Frequently asked questions about anabolic steroids (anabolics, AAS)
Do anabolic steroids really work?
Yes. In a randomized trial, men on testosterone and strength training gained 6.1 kg of fat-free mass in 10 weeks, considerably more than with training alone. The effect has been undisputed for decades; the discussion revolves around the health cost.
How dangerous are anabolic steroids for the heart?
In a Danish cohort with 1,189 users, the risk of heart muscle disease was 8.90-fold and the risk of heart attack 3.00-fold higher. Long-term users had weaker pump function and more plaque in the coronary arteries. Impaired small heart vessels were also found after quitting.
Does testosterone production recover after stopping?
In most men, the regulating hormones recover within a year. In some, however, testosterone remains low: in one study, 27.2 percent of former users were below the reference value years later. Anyone affected should have this checked at an endocrinology or andrology clinic.
Is possession of anabolic steroids a criminal offense in Germany?
Acquisition and possession of a not insignificant amount for doping in sport are prohibited under the German Anti-Doping Act, and trading and passing them on for doping purposes are prohibited in principle. The threshold amounts for each substance are set out in the Doping Substances Quantity Ordinance. For elite athletes, self-doping itself is additionally a criminal offense.
Are anabolic steroids prohibited in sport?
Yes, at all times, in and out of competition. The World Anti-Doping Agency lists them in the 2026 list under S1.1. Anyone competing in organized sport can find the Prohibited List and the medication database NADAmed at NADA.
Where can I get help with symptoms or with quitting?
The first point of contact is the family doctor’s practice; endocrinology, andrology and cardiology are the specialties; doctors are bound by medical confidentiality. For acute symptoms such as chest pain or shortness of breath, call the emergency number 112. The poison information centers of the German states, for example 089 19240 in Munich or 030 19240 in Berlin, advise on suspected poisoning, and NADA provides information on doping questions.
Related
- Related topicClenbuterol
- Related topicTrenbolone
- Related topicNandrolone decanoate
- Related topicBoldenone (Equipoise)
- Related topicDrostanolone (Masteron)
- Related topicOral-Turinabol (dehydrochlormethyltestosterone)
Sources
- Bhasin et al., N Engl J Med 1996 – supraphysiological testosterone, muscle mass and strength
- Windfeld-Mathiasen et al., JAMA 2024 – mortality of AAS users
- Windfeld-Mathiasen et al., Circulation 2025 – cardiovascular disease in AAS users
- Baggish et al., Circulation 2017 – cardiac function and coronary plaque
- Rasmussen et al., PLoS One 2016 – testosterone deficiency years after quitting
- Smit et al., Scand J Med Sci Sports 2021 – HAARLEM study, 100 men, 1 year
- Sagoe et al., Ann Epidemiol 2014 – global prevalence, meta-analysis
- Magnolini et al., BMC Public Health 2022 – counterfeit anabolic steroids on the black market
- Pope et al., Endocr Rev 2014 – Endocrine Society, health consequences of performance-enhancing drugs
- German Anti-Doping Act (Anti-Doping-Gesetz), § 2 to § 4 and annex
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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-09-27.