Why Athletes Use Losartan: Blood Pressure, Heart and Muscle Research
Losartan is a common prescription blood pressure drug, yet it keeps appearing in conversations among strength athletes and in sports medicine research on muscle injuries. Our editorial team looked at why physicians prescribe it to active people, what the evidence on muscle healing actually covers, and why self-medicating with it is a bad idea.
What losartan is and how it works
Losartan was the first angiotensin II receptor blocker (ARB) approved in the United States, introduced in the mid-1990s. It blocks the AT1 receptor, preventing angiotensin II from tightening blood vessels and triggering salt and water retention. The result is relaxed arteries and lower blood pressure.
Angiotensin II does more than constrict vessels. It stimulates aldosterone release, promotes thickening of the heart muscle and encourages fibrosis, the build-up of scar-like connective tissue, in the heart, kidneys and blood vessels. Blocking its receptor addresses several of these processes at once.
ARBs are close relatives of ACE inhibitors such as lisinopril. Both act on the renin-angiotensin system, but ARBs rarely cause the dry cough that leads many patients to stop ACE inhibitors. For that reason, losartan is often chosen for people who could not tolerate an ACE inhibitor.
Losartan is prescription-only in the US. Its FDA labeling covers hypertension, reduction of stroke risk in hypertensive patients with left ventricular hypertrophy, and diabetic kidney disease in people with type 2 diabetes. Dose selection, monitoring and adjustments are made by a physician.
Hypertension in athletes
High blood pressure is less common in athletes than in the general population, but it is far from rare. Older recreational athletes, larger strength and power athletes, and people with a family history are at higher risk. Many are unaware of their numbers because they feel healthy.
Some causes are specific to sport. Nonsteroidal anti-inflammatory drugs, decongestants, high-dose stimulants, energy drinks and heavy alcohol intake can all raise blood pressure. Anabolic-androgenic steroid use is particularly associated with elevated blood pressure, left ventricular hypertrophy and reduced heart function, as described by Baggish and colleagues and in the Endocrine Society statement on performance-enhancing drugs.
The 2017 ACC/AHA guideline (Whelton et al.) lowered the threshold for stage 1 hypertension to 130/80 mmHg. Under that definition, a meaningful share of active adults qualify, and lifestyle measures are the first step for most.
| Category (ACC/AHA 2017) | Systolic (mmHg) | Diastolic (mmHg) |
|---|---|---|
| Normal | <120 | <80 |
| Elevated | 120–129 | <80 |
| Stage 1 hypertension | 130–139 | 80–89 |
| Stage 2 hypertension | ≥140 | ≥90 |
When medication is needed, sports cardiologists usually prefer drugs that do not impair exercise capacity. ARBs and ACE inhibitors are favored because they do not limit heart rate response, unlike beta-blockers, and do not cause the fluid and electrolyte problems of diuretics. The 2020 ESC guidelines on sports cardiology reflect this preference.
Heart and kidney protection
Beyond lowering blood pressure, losartan has outcome data. The LIFE trial (Dahlöf et al., 2002) compared losartan with atenolol in more than 9,000 hypertensive patients with left ventricular hypertrophy. With similar blood pressure reduction, losartan led to fewer cardiovascular events, driven mainly by fewer strokes.
The RENAAL trial (Brenner et al., 2001) showed that losartan slowed kidney disease progression in people with type 2 diabetes and nephropathy. This kidney-protective effect partly explains why ARBs are a cornerstone in patients with protein in their urine.
In Marfan syndrome, a genetic connective tissue disorder relevant to tall athletes in basketball and volleyball, losartan was studied because it reduces TGF-beta signaling. The large trial by Lacro and colleagues (2014) found that losartan and atenolol slowed aortic root enlargement to a similar degree, tempering early hopes of a superior effect.
Athletes with Marfan syndrome or other aortic conditions need individualized assessment from a cardiologist regarding both treatment and sport participation. Medication does not make high-intensity or collision sports safe for everyone with these conditions.
Losartan and muscle injury research
The reason losartan comes up in sports medicine circles is fibrosis. After a muscle tear, the body repairs damage partly with scar tissue, which can reduce function and increase re-injury risk. TGF-beta1 is a key driver of that scarring, and angiotensin II increases TGF-beta activity.
Animal studies, notably by Bedair and colleagues (2008), showed that losartan given after a muscle injury in mice reduced fibrosis and improved regeneration. These findings generated considerable interest and some small clinical pilot work.
However, the evidence in humans is limited. There are no large randomized trials demonstrating that losartan speeds return to play or reduces re-injury in athletes. Using it outside of a clinical trial for this purpose is off-label and unproven.
- Animal data suggest less fibrosis and better muscle regeneration.
- Human evidence is preliminary and does not support routine use for injuries.
- Standard rehabilitation, progressive loading and time remain the foundation of muscle injury recovery.
Losartan has also been discussed as a way to counter heart remodeling caused by anabolic steroids. While ARBs do treat hypertension and hypertrophy in clinical practice, no drug neutralizes the cardiovascular risks of steroid use. Stopping the cause and getting a cardiology evaluation are the appropriate steps.
Side effects, contraindications and anti-doping status
Losartan is generally well tolerated, but it is not harmless. Dizziness, especially when standing up quickly, is common early in treatment. Exercising in the heat, becoming dehydrated or combining it with other blood pressure drugs can amplify low blood pressure.
It can raise potassium levels and affect kidney function, particularly when combined with potassium supplements, salt substitutes, potassium-sparing diuretics or NSAIDs. Physicians typically check blood potassium and creatinine after starting therapy. The combination of an ARB, a diuretic and an NSAID is a known risk for acute kidney injury.
The US label carries a boxed warning: drugs acting on the renin-angiotensin system can cause injury and death to the developing fetus. Losartan must be stopped as soon as pregnancy is detected, and women who may become pregnant need careful counseling.
Losartan is not on the World Anti-Doping Agency Prohibited List, unlike diuretics or beta-blockers in certain sports. Athletes in tested sport should still verify current rules with USADA or their governing body, and should never use prescription drugs without a medical indication.
The Editorial Team's Conclusions
Losartan is a well-established medication for high blood pressure with proven benefits for the heart and kidneys. For active people who need treatment, it is often a good choice because it does not impair exercise capacity.
Research on muscle healing is interesting but remains largely confined to animal models. It does not justify off-label use for injuries.
The safest approach for athletes is to check blood pressure regularly, address causes such as stimulants or steroid use, and let a physician decide on medication.
You might also be interested in our articles on amlodipine for athletes, on how anabolic steroids affect the heart, and on home blood pressure monitoring.
References
- Dahlöf B, Devereux RB, Kjeldsen SE, et al. Cardiovascular morbidity and mortality in the Losartan Intervention For Endpoint reduction in hypertension study (LIFE): a randomised trial against atenolol. Lancet. 2002;359(9311):995–1003.
- Brenner BM, Cooper ME, de Zeeuw D, et al. Effects of losartan on renal and cardiovascular outcomes in patients with type 2 diabetes and nephropathy. N Engl J Med. 2001;345(12):861–869.
- Lacro RV, Dietz HC, Sleeper LA, et al. Atenolol versus losartan in children and young adults with Marfan's syndrome. N Engl J Med. 2014;371(22):2061–2071.
- Bedair HS, Karthikeyan T, Quintero A, et al. Angiotensin II receptor blockade administered after injury improves muscle regeneration and decreases fibrosis in normal skeletal muscle. Am J Sports Med. 2008;36(8):1548–1554.
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. Hypertension. 2018;71(6):e13–e115.
- Pelliccia A, Sharma S, Gati S, et al. 2020 ESC Guidelines on sports cardiology and exercise in patients with cardiovascular disease. Eur Heart J. 2021;42(1):17–96.
- Baggish AL, Weiner RB, Kanayama G, et al. Cardiovascular toxicity of illicit anabolic-androgenic steroid use. Circulation. 2017;135(21):1991–2002.
