A popular erectile dysfunction medication could hold an unexpected clue for muscle recovery, according to laboratory research from Italy. Scientists found a potential association between Cialis, also known as tadalafil, and processes involved in muscle regeneration.

The study, published in Molecular Biology Reports, tested tadalafil on mouse muscle cells in a laboratory. Over seven days, researchers examined how the medication affected cell growth, survival and development.

Tadalafil increased the number of muscle precursor cells, which participate in the early stages of muscle formation. The treatment also helped more of those cells survive during the experiment.

Researchers found additional signs that tadalafil could support muscle repair by promoting growth and reducing cell death. Those results offered an encouraging signal, but they did not establish that the drug builds muscle or improves recovery in people.

The experiment also produced a significant caution. Although tadalafil increased and preserved precursor cells, it delayed their development into fully mature muscle cells.

That distinction is critical because successful regeneration requires precursor cells to mature and form functional muscle tissue. The study did not demonstrate an increase in muscle size, strength or function in humans.

The research was conducted using mouse muscle cells rather than people, limiting how broadly its findings can be applied. Results seen under laboratory conditions may differ from what happens in the human body.

The study also lasted only seven days. Researchers acknowledged that additional work is needed to understand any long term effects and determine whether the observed cellular changes could eventually have therapeutic value.

Study author Dr. Cristina Antinozzi, a researcher in the Endocrinology Unit at the University of Rome Foro Italico, described the findings as an “encouraging look at how tadalafil might be repurposed to support muscle tissue repair and regeneration.”

Antinozzi nevertheless emphasized that the research remains preliminary. The biological activity observed in mouse cells does not prove that Cialis can build muscle or improve recovery in people.

“While more work is needed, this research opens up exciting new possibilities for future therapeutic strategies in muscle recovery, though it also highlights the need to monitor how such mechanisms might be viewed or misused in sports and performance contexts,” she told Fox News Digital.

Dr. Kien Vuu, a radiologist and founder of VuuMD Performance and Longevity in Los Angeles, was not involved in the study. He called the research an “intriguing early finding.”

“In mouse muscle cells studied in a laboratory, tadalafil — the active ingredient in Cialis — helped muscle precursor cells grow and survive, but also delayed their maturation into muscle fibers,” Vuu told Fox News Digital.

“Successful regeneration ultimately requires those cells to mature and form functional muscle tissue. This experiment didn't establish that outcome.”

Vuu said the findings are worth studying from a longevity perspective because muscle loss associated with aging contributes significantly to frailty, metabolic dysfunction and loss of independence. Even so, he stressed that the experiment was not a clinical trial.

“However, this was a laboratory cell study, not a clinical trial,” he said. “We need animal studies and eventually human trials examining actual muscle mass, strength, physical function and safety before drawing conclusions about clinical use.”

For now, Vuu said resistance training, adequate protein and quality sleep remain the “most reliable ways” to protect muscle with age. The new findings do not displace those established lifestyle practices.

Tadalafil also carries meaningful risks, according to Vuu, including dangerous reductions in blood pressure when it is combined with nitrates. He warned that people should not begin using the medication for muscle building on the strength of this laboratory study.

The findings therefore offer a potential direction for future investigation, not a new muscle treatment. Researchers would still need to determine whether tadalafil can produce functional muscle benefits and whether such use would be safe.