SGLT2 inhibitors (sodium–glucose cotransporter‑2 inhibitors) benefits relevant to athletes using them for enhancement:
- Reduced body weight, they promote urinary glucose loss that can lower body weight and fat mass, which may help athletes in weight-class or aesthetic sports.
- Lowered blood glucose, a decreased blood glucose independently of insulin, potentially reducing hyperglycemia-related performance impairments in athletes with insulin resistance.
- Improved cardiovascular markers, some agents show reductions in blood pressure and improvements in cardiovascular outcomes (reduced heart failure risk) which could support endurance and recovery in certain athletes.
- Renal protection, slowed progression of kidney disease in at‑risk individuals, potentially beneficial for long‑term athlete health under heavy training loads.
- Metabolic substrate shift, by promoting mild ketosis and greater fat oxidation, they may increase reliance on fat as fuel during prolonged exercise, which could preserve glycogen in endurance settings.
Have you had any experience with these drugs yourself, or perhaps know someone who has used them?
To be honest, I have significant doubts about the practical use of SGLT2 inhibitors by healthy athletes for performance enhancement. Many of the proposed benefits sound interesting in theory, but the real question is how relevant they are in practice and whether athletes are actually using them for this purpose.
First, the idea of a highly insulin-resistant athlete is somewhat questionable. Exceptions certainly exist, particularly among heavyweight powerlifters, strongmen, or off-season bodybuilders consuming extremely high caloric intakes while carrying substantial amounts of body fat. However, for most athletes—especially those involved in endurance, team, combat, or mixed sports—insulin sensitivity is generally quite good.
Let's go through the main arguments one by one:
Weight Loss
Today, there are far more effective tools available for weight loss and appetite control, most notably GLP-1 receptor agonists. Compared to them, the weight-loss effect of SGLT2 inhibitors appears relatively modest.
Lower Blood Glucose
This effect is primarily relevant to individuals with impaired glucose metabolism. For a healthy athlete with normal insulin sensitivity, it is difficult to see how lowering blood glucose would provide any meaningful performance advantage.
Blood Pressure Reduction
When it comes to athletes with elevated blood pressure, many consider telmisartan one of the most interesting options available. Beyond blood pressure control and renal protection, it is also associated with potential cardiovascular benefits, and some evidence suggests it may help reduce left ventricular hypertrophy. Because of its overall profile, it is frequently discussed not only in athletic circles but also in longevity-oriented communities.
Additionally, although uncommon, blockade of the renin-angiotensin-aldosterone system (RAAS)—through either ACE inhibitors or ARBs such as telmisartan—may slightly reduce hemoglobin and hematocrit levels. This can be particularly beneficial for individuals using testosterone or anabolic steroids.
In cases where testosterone-induced erythrocytosis develops, some physicians favor ACE inhibitors or ARBs because suppression of the RAAS may modestly reduce erythropoietic stimulation. While the effect is usually small, it may still be clinically relevant in certain situations.
By contrast, SGLT2 inhibitors are known to increase hematocrit. Initially, this was thought to be simply a result of hemoconcentration due to fluid loss. However, subsequent research suggests that part of the effect is driven by increased erythropoietin production and stimulation of erythropoiesis. For bodybuilders and strength athletes, particularly those already dealing with elevated hematocrit from androgen use, this could become a significant concern.
Improved Endurance Through Greater Fat Oxidation
It is important to recognize that endurance is not a single, uniform quality. Any potential advantage from increased fat utilization would primarily apply to prolonged aerobic activities performed below or near the aerobic threshold.
This has limited relevance to bodybuilding, recreational fitness, most combat sports, team sports, and many other disciplines where carbohydrate metabolism plays a dominant role in performance.
Kidney Protection
This is undoubtedly an important medical benefit, but it is primarily relevant to the treatment and prevention of kidney disease in at-risk individuals. Managing kidney health and kidney disease is a matter for physicians, not a performance-enhancement strategy for healthy athletes. Overall, SGLT2 inhibitors appear to be medications designed to treat specific metabolic, cardiovascular, and renal conditions.