Electrical, radiofrequency, ultrasound and massage devices

Key takeaways

• Electrical stimulation has one positive sham-controlled trial, from the maker's team. In 81 men, a wearable low-current device worn 30 minutes a day for 24 weeks gave 24.4 more hairs per cm2 than sham (95% CI 4.9 to 43.9) in the per-protocol group of 38 active and 25 sham users (Chacon-Martinez 2026). An earlier uncontrolled pilot of 21 men reported +19.3% density at 6 months by authors affiliated with the developer (Jellard 2025). No independent replication was found.
• Radiofrequency evidence is small and mostly unblinded. A single-blind sham study of 24 men reported a 54% clinical response (Tan 2019), and a 25-patient series reported +31.6% density (Verner 2018). In 30 women on 5% minoxidil, radiofrequency microneedling beat fractional CO2 laser plus minoxidil (Hilal 2026).
• Iontophoresis and ultrasound are delivery tricks, not growth stimulators. A 20-person pilot of iontophoresis with 6% dutasteride gel monthly for four sessions reported better density at 8 weeks, with no control group (Cedirian 2025). More drug in the skin could also mean more drug in the body. Similar claims for microneedling failed histology testing (Dhurat 2019).
• Standardized scalp massage is plausible but unproven. Nine healthy men massaged 4 minutes a day for 24 weeks; mean hair thickness rose from 0.085 to 0.092 mm with no control group (Koyama 2016). A retrospective survey of self-assessed sufferers found 68.9% of those who tried massage perceived stabilization or regrowth, but it was self-reported with heavy selection and written by authors tied to a hair-loss education business (English 2019).
• Heated, vibrating and scalp-wellness devices had no published hair-growth trials in our searches.
• LED caps are normally judged together with laser caps. A 2025 meta-analysis of 38 studies (3,098 patients) found a density benefit with high heterogeneity (Perez 2025); see low-level laser therapy.

How it might work

Cell studies show electrical stimulation can raise hair-related gene activity in dermal papilla cells and made more hair in a mouse model, but that does not show a skin-surface device does the same in a living scalp. Radiofrequency gently heats tissue, and fractional radiofrequency microneedling combines needles with radiofrequency (see microneedling). Massage may stretch cells in the dermis, based on lab work in the Koyama study.

What the studies show

• Chacon-Martinez 2026: double-blind sham RCT, 81 men, 24 weeks, +24.4 hairs per cm2 vs sham (Chacon-Martinez 2026).
• Hilal 2026: split-scalp RCT in 30 women (Hilal 2026).
• Tan 2019 and Verner 2018: small radiofrequency studies, as above.
• Cedirian 2025 and Koyama 2016: uncontrolled pilots, as above.

The evidence is limited: mostly short, small, uncontrolled or maker-linked studies.

Side effects and safety

Reported effects are mild, such as temporary tingling or redness. The bigger issues are cost, unproven claims, and methods that increase absorption of whatever you apply. Ask a doctor before using electrical devices if you have an implanted pacemaker or defibrillator.

Bottom line

These devices sit below minoxidil, finasteride and light therapy on the treatment ladder. If you try a wearable, prefer one with a refund policy and compare against start-of-trial photos, and do not pay clinic prices for ultrasound or iontophoresis combinations expecting growth-factor delivery. Gentle scalp massage is safe for most people but should not replace proven treatment. Discuss with a doctor.