D-Ribose is a naturally occurring sugar that plays a critical role in the production of adenosine triphosphate (ATP), the primary energy carrier in all cells, including those of the heart muscle. Some scientific studies, mostly small-scale and preliminary, have investigated D-Ribose supplementation in individuals with heart disease, particularly those with chronic coronary artery disease, congestive heart failure, or myocardial ischemia. The rationale is that compromised heart tissue may have impaired ATP synthesis, and supplemental D-Ribose could potentially help replenish cellular energy stores and improve cardiac function or exercise tolerance.

Clinical trials have shown mixed but generally modest benefits. For example, some small randomized controlled trials and open-label studies have reported improvements in diastolic function, exercise capacity, and quality of life in patients with chronic heart failure or ischemic heart disease. However, these studies are limited by small sample sizes, short duration, and lack of blinding. Meta-analyses and larger trials are lacking, and D-Ribose is not widely endorsed in clinical guidelines for heart failure or other cardiac conditions.

In summary, the use of D-Ribose to support heart weakness is based on a plausible biochemical rationale and some early clinical evidence, but current scientific validation is limited and the quality of evidence is low (rated 2/5). Larger, well-designed studies are needed to establish efficacy and safety.