Researchers at the University of Rome Foro Italico have found that tadalafil, the active ingredient in the erectile dysfunction drug Cialis, may play a role in muscle cell regeneration, according to a new study published in the journal Molecular Biology Reports.
The research, conducted in a laboratory setting on mouse muscle cells over a seven-day period, examined how the drug affected the growth, survival and development of muscle cells.
The scientists found that tadalafil increased the number of muscle precursor cells, the early building blocks of muscle formation, and helped more of those cells survive. The drug also appeared to support muscle repair by encouraging cell growth and reducing cell death.
However, the study also found a drawback: tadalafil delayed the development of fully mature muscle cells. That means the drug may help create and sustain more regenerative cells without necessarily translating into bigger or stronger muscles in humans.
The researchers were careful to note the limits of their findings. The experiment was conducted in mouse models, not humans, and lasted only seven days, meaning the long-term effects of the drug on muscle tissue remain unknown.
An ‘encouraging’ but early finding
Study co-author Dr. Cristina Antinozzi, a researcher in the Endocrinology Unit at the University of Rome Foro Italico, described the results as an encouraging look at how tadalafil might one day be repurposed to support muscle tissue repair and regeneration.
“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,” Antinozzi said.
Dr. Kien Vuu, a radiologist and founder of VuuMD Performance and Longevity in Los Angeles who was not involved in the research, called the findings an intriguing early signal but cautioned against drawing broader conclusions.
“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. That’s a fascinating biological signal, but it’s far from proving that Cialis builds muscle or improves recovery in people,” Vuu said.
He added that successful muscle regeneration ultimately depends on those precursor cells maturing into functional tissue, an outcome this particular experiment did not establish.
Why it matters for aging
Vuu said the topic is worth further study because age-related muscle loss contributes significantly to frailty, metabolic dysfunction and loss of independence in older adults. But he stressed that a laboratory cell study is a long way from a clinical trial.
“We need animal studies and eventually human trials examining actual muscle mass, strength, physical function and safety before drawing conclusions about clinical use,” Vuu said.
He added that proven lifestyle habits — resistance training, adequate protein intake and quality sleep — remain the most reliable ways to protect muscle as people age.
Vuu also flagged that tadalafil carries real risks, including dangerous drops in blood pressure when combined with nitrate medications.
“So, people should not take it for muscle-building based on these findings,” he said.
