Bottom growth is the enlargement of the clitoris that happens when a person takes testosterone as part of masculinizing hormone therapy. It’s one of the earliest and most noticeable changes on testosterone, often beginning within the first few weeks of treatment. The tissue grows to resemble a small phallus, typically reaching 1 to 3 centimeters in length, though individual results vary. It is a permanent change that will not reverse if testosterone is stopped.
Why Testosterone Causes This Change
The clitoris and the penis develop from the same embryonic structure, called the genital tubercle. During prenatal development, exposure to androgens (primarily a potent form of testosterone called dihydrotestosterone, or DHT) is what causes that shared tissue to grow into a penis. Without significant androgen exposure, the same tissue develops into a clitoris. The underlying biology doesn’t disappear after birth. The tissue retains androgen receptors throughout life, which means it can still respond to testosterone later on.
When a person begins testosterone therapy, their body converts some of that testosterone into DHT through an enzyme naturally present in genital tissue. DHT binds to androgen receptors in the cells and triggers growth, essentially resuming a developmental process that the tissue was always capable of. This is the same mechanism that drives genital growth during typical male puberty.
When Growth Starts and How Long It Lasts
Bottom growth is one of the first physical changes on testosterone. Many people notice increased sensitivity and slight enlargement within the first one to three months. Growth tends to be most rapid in the first year, then gradually slows. Most people see the majority of their growth within the first one to two years of hormone therapy, though some continue to experience subtle changes beyond that window.
The pace and extent of growth vary from person to person, influenced by genetics, DHT levels, and individual tissue response. There’s no reliable way to predict exactly how much growth someone will experience.
What It Looks and Feels Like
The enlarged clitoris, sometimes called a “T-dick” or “growth,” takes on a more prominent, phallic appearance. It becomes more visible outside the clitoral hood and may become noticeably erect during arousal, similar to a small penis. The glans (head) tends to become more defined.
Sensitivity changes significantly. In the early weeks, many people describe a tingling sensation or heightened awareness in the genital area, sometimes to the point of being distracting. The tissue becomes more responsive to touch, especially during arousal. For most people, this initial hypersensitivity settles down over time as they adjust, though the area generally remains more sensitive than it was before testosterone.
Libido also tends to increase noticeably soon after starting testosterone, and the combination of heightened sex drive with new genital sensitivity can feel like a lot at once. This is normal and typically becomes more manageable within a few months.
Permanence
Bottom growth is irreversible. Unlike some testosterone effects (such as body fat redistribution or menstrual changes) that can reverse if a person stops taking testosterone, clitoral growth is permanent. UCSF and other major gender health programs list it alongside voice deepening and facial hair growth as a change that persists regardless of whether hormone therapy continues. This is worth knowing before starting testosterone, since the growth cannot be undone without surgery.
Hygiene and Daily Comfort
As the tissue grows and the clitoral hood shifts, a small buildup of dead skin cells and natural oils (called smegma) can accumulate in the folds around the growth. This is the same substance that collects under the foreskin of a penis, and it’s managed the same way: gentle, regular cleaning.
Wash the area with warm water and a mild, fragrance-free soap. Gently retract the hood to clean underneath. Avoid products with perfumes, dyes, or alcohol, since the tissue is sensitive. Dry the area thoroughly afterward, as trapped moisture can lead to irritation or infection. Breathable cotton underwear helps with airflow. If you notice persistent redness, unusual bumps, or discomfort that doesn’t resolve with regular cleaning, it’s worth getting it checked out.
Clothing and Physical Comfort
Increased sensitivity can make certain clothing uncomfortable, especially tight underwear or pants with rough seams. Soft, breathable fabrics work best during the adjustment period. Some people find that switching underwear styles helps, either to something with more room in front or to a style that provides light support or padding against friction. Overly tight clothing can press against the growth in ways that range from mildly distracting to genuinely uncomfortable, so giving yourself room to experiment with what works is practical advice.
Some people also find that their relationship with packing changes as bottom growth progresses. A packer that felt right before may feel different against tissue that’s now more sensitive and prominent.
Intimacy and Sensation
Bottom growth changes how arousal and orgasm feel. The tissue becomes more erectile, meaning it stiffens more noticeably during arousal, and many people report that sexual sensation shifts in character. What felt good before testosterone may feel different, and new kinds of stimulation may become pleasurable. This is a process of discovery that evolves over months.
Vaginal dryness is a common side effect of testosterone that often coincides with bottom growth. If penetrative sex is part of your life, a water-based lubricant can help with comfort. Communication with partners about what feels good, what’s changed, and what you need becomes especially important during this period of rapid physical change.
Bottom Growth and Surgery
For some transmasculine people, bottom growth serves as the foundation for a surgical procedure called metoidioplasty. This surgery releases the enlarged clitoris from its surrounding ligaments and repositions it to function more like a small penis. The clitoral body naturally remains shortened and curved due to attachments to the suspensory ligaments and surrounding tissue. Metoidioplasty releases these connections to create a free-hanging phallus.
Post-surgical length varies. One review in the Indian Journal of Plastic Surgery found an average neophallus length of about 6.5 centimeters, with a range of 4 to 10 centimeters. The results depend heavily on how much growth a person achieved from testosterone before surgery, which is why surgeons typically recommend at least one to two years of hormone therapy beforehand. Metoidioplasty is a very different procedure from phalloplasty (which constructs a full-sized penis from donor tissue elsewhere on the body), and the choice between them involves trade-offs in size, sensation, scarring, and surgical complexity.