Bottom Growth & FTM Pumps: The Honest Guide
Bottom growth is clitoral growth on testosterone. It usually starts 3–6 months after you begin T, years one through three carry most of the change, and typical growth is 1–4 cm, with studies reporting averages of 2.5–4.6 cm. It is generally considered permanent.
A pump works from the first session. The vacuum drives blood into the tissue, which swells past the size it normally holds while you use it, and what follows is engorgement, warmth and heightened sensation. It works on T and it works pre-T.
This page covers what the hormone does and what the gear does.
What is bottom growth?
Bottom growth is the enlargement of clitoral tissue that testosterone causes. In community language it is your t-dick.
It is a standard effect of T, alongside voice change and body hair, and it happens whether or not you do anything to encourage it. For the full definitional breakdown, including sensation changes and terminology, see what is bottom growth.
When does bottom growth start on T?
FOLX Health puts typical onset at 3–6 months after starting testosterone. Some people notice something in the first weeks. Some wait past the six-month mark.
Years one through three are where most of it happens. That surprises people who expect the first six months to do the heavy lifting. It is a years-long process, and the pace is set by your body, your dose, and your genetics.
Low-dose testosterone still typically produces some bottom growth. Microdosing changes the timeline more reliably than it changes the destination. That is a dose conversation for your prescriber.
Stage by stage: bottom growth stages. The timeline in detail: how long bottom growth takes on testosterone.
How much growth is typical?
Typical bottom growth on testosterone is 1–4 cm. Studies report averages between 2.5 and 4.6 cm, per FOLX Health.
Those figures describe populations rather than individuals. The full numbers discussion is at how big does bottom growth get.
The first months are often uncomfortable
Early bottom growth commonly brings hypersensitivity: pressure, itching, burning, sensitivity against underwear, and erections that arrive on their own schedule. FOLX Health notes this usually resolves by around six months.
Softer fabrics. Roomier cuts. Lube or moisturiser. Less packing time while things are most reactive. That handles most of it. Detail: does bottom growth hurt.
What does an FTM pump actually do?
A pump creates a vacuum. Blood moves into the tissue under it. During the session the tissue expands past the size it normally sits at, and afterward you get engorgement, warmth, and for most people heightened sensation.
Those are session effects. They happen on your first session and they happen whether or not you are on T. FOLX Health covers pumping in both pre-T and on-T contexts and calls our Trans Masc Pump "easy and effective."
People pump for the sensation, for the visual through the cylinder, and for the ritual of spending time with their own anatomy on purpose.
A number of surgeons ask for pumping on both sides of metoidioplasty, to support circulation. If surgery is on your horizon, raise it with your surgical team. The evidence discussion in full: does pumping actually work.
Which pump should you start with?
Three pumps, three jobs. All use cylinders shaped for bottom-growth anatomy rather than borrowed from another product, all are translucent so you can see what is happening, and all work pre-T and post-T.
- Trans Masc Pump 2.0. Manual, single cylinder. The simplest way in.
- Trans Masc Pump Deluxe. Manual, three cylinder sizes, measuring stickers. Get this one to dial in fit, or to track against your own baseline.
- Trans Masc Pro Pump. Electric, push-button, digital kPa gauge, auto, manual and pulse modes, fully waterproof, USB-C rechargeable, three cylinders with comfort cushions. Get this one for pressure as a number rather than a feel, or if repeated squeezing is difficult for your hands.
Each comes as a kit with the Jack stroker: 2.0 + Jack, Deluxe + Jack, Pro + Jack.
Every piece carries a One-Year Maker's Warranty. Line by line: manual versus electric. Everything ships in a plain box with no branding on the outside.
How do you pump safely?
Warm up first. Warm water on the pump, a warm towel on you. Dry everything, then lube both yourself and the cylinder rim. Lubricant directly reduces discomfort.
Start at low pressure. Your first sessions run 5–10 minutes and stop there. Never exceed 30–45 minutes, cap it at 4–5 sessions a week, and never more than 3 in a day.
On a manual gauge, stay at or below about 5 lbs. On the Pro's digital gauge, beginners work at 5–15 kPa. Your tissue should never fill the cylinder completely. If it does, size up.
Pain means stop. The full walkthrough is at how to start pumping for bottom growth.
Is bottom growth permanent?
Generally, yes. FOLX Health describes it as a permanent change: once the tissue grows on testosterone, it typically stays, even if you stop T later. Same category as voice deepening.
There are anecdotal reports of partial reversal in people who were on T briefly or at low doses. Those are individual accounts, not studies. If reversibility matters to your decision, the full discussion is at is bottom growth permanent.
Frequently asked questions
What is bottom growth?
Clitoral growth caused by testosterone, commonly called a t-dick. Typical growth is 1–4 cm with study averages of 2.5–4.6 cm, per FOLX Health, and it usually begins 3–6 months into T.
When does bottom growth start on testosterone?
Usually 3–6 months in, per FOLX Health. Most of it arrives during the first three years. Some people notice sensation changes in the first weeks; others notice nothing for months.
What does an FTM pump do?
It fills the tissue with blood during a session. The tissue expands beyond its everyday size while you use it, and you get engorgement, warmth and heightened sensation. It works from the first session, on T or pre-T.
Can you pump before starting T?
Yes. The mechanism is blood flow, not hormones, and FOLX Health covers pumping pre-T and on-T. Our cylinders work at either stage. See bottom growth without T.
Is bottom growth permanent?
Per FOLX Health, generally yes, and it typically remains after stopping testosterone. Anecdotal reports of partial reversal exist for short-term or low-dose T.
How big does bottom growth get?
Typical growth is 1–4 cm, with studies reporting averages of 2.5–4.6 cm, per FOLX Health. Everyone's range is their own.
