Fox News reported on October 13, 2026 on a cell study from researchers at the University of Rome Foro Italico, published in Molecular Biology Reports. It found that tadalafil, the active ingredient in Cialis, pushes skeletal-muscle progenitor cells into a more proliferative, regeneration-ready state. The Toronto Sun, Bioengineer.org and others followed during the week. The team, led by Cristina Antinozzi and Luigi Di Luigi, exposed C2C12 mouse myoblasts to 1 micromolar tadalafil for up to seven days. The idea was to mimic sustained use rather than a single dose.

Why It Matters

Tadalafil is the workhorse of ED telehealth. Hims, Ro and others sell it daily and increasingly in compounded combinations, often marketed to men who already buy TRT, peptides and longevity stacks. A headline like "ED drug may boost muscle" will travel through that audience much faster than the caveats, so expect it to turn up in performance-and-longevity marketing. The scientific reading is narrower. It adds muscle to the list of tissues where PDE5 inhibition affects nitric-oxide/cGMP signalling, and it gives sarcopenia researchers a cheap, generic, well-characterised molecule to study. It also follows last month's **tadalafil–glaucoma** signal, so tadalafil is now being studied for effects well beyond ED, both good and bad. Anti-doping bodies will be watching too.

The results cut both ways. Tadalafil increased cell proliferation and survival at every time point and raised early myogenic factors. It also delayed terminal differentiation: treated cells formed fewer mature, myosin-positive myotubes and kept higher levels of Pax7 and Myf6, markers of a more stem-like state. In Bioengineer.org's summary, the drug didn't speed up muscle formation. It kept cells "poised in an earlier, more regenerative state," which is the profile researchers want when looking for therapies for muscle-wasting conditions such as sarcopenia and muscular dystrophy.

The authors and outside experts were careful about what it means. Antinozzi told Fox News Digital the work opens "exciting new possibilities" for muscle repair, but "also highlights the need to monitor how such mechanisms might be viewed or misused in sports and performance contexts." Dr. Kien Vuu, who was not involved, called it "a fascinating biological signal, but it's far from proving that Cialis builds muscle or improves recovery in people." The study used one mouse cell line, in a dish, for one week.

Sources

See also: Tadalafil–glaucoma signal · FDA peptide compounding push.

Update — 2026-10-20

Initial entry — story first created.