Devices
The science is plausible. The commitment is the problem — and that is where most users give up.
Do they work?
Traction devices apply sustained stretch to the penis, which in principle triggers new tissue growth — the same mechanism used in orthopaedic limb lengthening. There is published support for the approach in the British Journal of Urology and the Journal of Sexual Medicine.
Unlike lengthening surgery, an extender can increase both flaccid and erect length. That is a genuine advantage — ligament release only affects flaccid length.
The catch is dose. Meaningful results require 1,000 hours or more under tension, typically four hours a day for six to eight months. Most men wear the device for a month or two, conclude the gains are not worth the inconvenience, and stop. In practice, a significant permanent length gain is rarely achieved.
Comfort decides adherence
Conventional extenders exert pressure through a plastic loop behind the glans. That point becomes tender quickly, which limits daily wear time — and wear time is the only thing that determines whether it works.
Vacuum-based designs seal the glans in a cup and transmit tension along the shaft via a belt, avoiding that pressure point. Some users tolerate these for considerably longer. Finding a device you will actually wear matters more than any specification.
Versus filler
Length. Inexpensive. Requires 1,000+ hours of commitment over many months, with modest and uncertain results.
Girth. Immediate and predictable, in a single 30-minute visit. Considerably more expensive, and resorbs over 1–2 years.
They are not competitors — they address different dimensions. Some patients use both.
The comfort problem
The key to getting a result from an extender is finding one comfortable enough to wear for the maximum time under tension. Nothing else about the device matters as much.
Most extenders are at their most irritating exactly where the plastic loop passes behind the glans. That is the point where the metal tension bars press on the head in order to stretch the whole shaft — and it is why most men stop wearing them.
Phallosan takes a different approach: it seals the glans in a vacuum bell and transmits tension along the shaft through an elastic belt worn around the waist. There is no loop behind the head. For some men that allows considerably longer daily wear than a bar-and-loop device.
It is also discreet enough to wear under clothing, and can be worn overnight — which matters, because the target is roughly 1,000 hours of cumulative tension.
Straight comparison
They are not really competing products. One is cheap and slow and needs your patience; the other is expensive and immediate.
A lot of patience is required for any extender. The science is sound; the adherence is the hard part. Individual results vary from person to person.
The link above is an affiliate link. Androfill does not manufacture or sell traction devices.
Discreet, physician-led care at ten clinics across the United States.
Last reviewed on 30 July 2026.
Medically reviewed by Dr Gary Horn — founder of Androfill, consultant plastic and reconstructive surgeon and uro-andrologist, GMC 4267803.
General information only, not a substitute for a consultation. Individual results vary from person to person.