What Is a Prosthetic Testicle and How Does It Work?

A prosthetic testicle is a silicone or saline implant placed inside the scrotum to restore its natural appearance after a testicle has been removed or was never present. These devices have been available since 1941, and while they serve no hormonal or reproductive function, they address something that matters to many patients: how their body looks and feels to them.

What They Are Made Of

Silicone has been the dominant material for testicular prostheses worldwide since the mid-twentieth century. In the United States, however, silicone testicular implants were banned over theoretical health concerns, which pushed manufacturers toward saline-filled alternatives.¹ That regulatory split means your options depend partly on where you live. In much of Europe, South America, and Asia, solid silicone elastomer implants remain the standard. In the U.S., the FDA-cleared option is a saline-filled silicone shell.

The practical difference for the patient comes down to feel. A common complaint among implant recipients is that the prosthesis feels too firm compared to the natural testicle. In one study, 60% of patients with implants said the device felt harder than expected.² Saline-filled versions tend to feel somewhat softer and more natural to the touch, which is one reason they gained traction beyond just the regulatory vacuum in the U.S. Researchers are also exploring newer approaches, including 3D-printed molds that allow custom-shaped prostheses matched more closely to a patient’s anatomy, along with antibacterial and anti-inflammatory surface coatings meant to reduce complications after surgery.³

Who Gets One and Why

The most common reason for a prosthetic testicle is testicular cancer. When a tumor is found, the standard treatment is radical orchiectomy, the surgical removal of the affected testicle. After that procedure, the patient is left with one testicle or, in rarer bilateral cases, none. Other reasons include undescended testicles that were removed in childhood, torsion injuries that led to testicular loss, trauma, and differences of sex development where one or both testes never formed properly.

Not everyone who loses a testicle wants a prosthesis. A qualitative study of men with testicular cancer found that some declined the implant because they felt the loss of one testicle was not visually obvious, did not threaten their sense of masculinity, and did not justify additional surgery. Others had safety concerns about having a foreign object implanted.⁴ That decision is deeply personal, and surgeons generally agree the implant should always be offered but never pushed.

How Satisfaction Holds Up

The evidence consistently shows that most people who receive a testicular prosthesis are glad they did. A systematic review and meta-analysis of patient-reported outcomes found that implantation results in high satisfaction and low decision regret across studies.⁵ Individual studies reinforce this. In a Portuguese survey of testicular cancer survivors with implants, overall satisfaction was rated excellent or good in about 98% of respondents, and roughly 88% said they would make the same decision again.⁶

Satisfaction does not mean there are no complaints. The same Portuguese study found that the most common gripe was inappropriate texture, reported by about 46% of recipients. Size mismatch and positioning issues were less frequent but still present.⁷ In a smaller American study, 20% felt the implant sat too high in the scrotum and 30% said it did not match their size expectations.⁸ These complaints suggest that better preoperative sizing and more realistic expectation-setting could push satisfaction even higher.

The Body Image Question

Beyond cosmetic satisfaction with the device itself, there is real evidence that having the prosthesis placed changes how patients feel about their bodies. A study comparing orchiectomy patients who received an implant at the time of surgery with those who did not found significant differences. Patients without a prosthesis more frequently reported that they were still missing the removed testicle and felt ashamed about their body image. Their partners also complained more often about the patient’s appearance. On multivariable analysis, having the prosthesis placed was associated with roughly 60% lower odds of experiencing decision regret.⁹

About 59% of men in the Portuguese survey said that having a normal-looking scrotum was extremely important or important for their self-esteem.¹⁰ That leaves a substantial minority for whom it genuinely does not matter much, which helps explain why prosthesis uptake rates vary widely across clinics. The psychological benefit is real for many, but it is not universal, and that is fine.

Complications and What Can Go Wrong

Testicular prosthesis placement is a relatively minor surgery, but it carries real risks. A study of 149 patients with saline-filled implants found postoperative adverse events in about 19%. The most concerning complication was extrusion, where the implant pushes through the surrounding tissue, occurring in roughly 3% of cases. Device-related pain affected about 3%, infection about 1%, and deflation of the saline fill about 1%.¹¹

Extrusion is the complication that gets the most clinical attention. It usually involves the implant migrating upward toward the inguinal ring, though in rare cases it can push directly through the scrotal skin. One case report documented a complete expulsion of the implant through an otherwise healthy scrotum just three weeks after surgery.¹² Cases like that are unusual, but they underscore why surgical technique and appropriate sizing matter.

Migration that falls short of full extrusion is more common. Patients sometimes notice the implant has shifted position over time, sitting too high or drifting to one side of the scrotum. This does not always require additional surgery. Some patients adapt to the new position without discomfort, while others eventually need a reoperation to move or replace the prosthesis.

Getting the Size Right

One of the trickier aspects of prosthesis placement is picking the right size. In patients who still have one natural testicle, the goal is symmetry. Traditional measurement tools used in urology are not always precise enough for this purpose. One technique that has been described uses a standard tongue depressor to measure the remaining testicle and match it to the correct implant size, offering a simpler and more reliable alternative to conventional methods.¹³

Available implants typically range from under 15 mL to about 30 mL in volume. When there is no remaining natural testicle for comparison, the choice comes down to patient preference, body frame, and the surgeon’s judgment. Given that size mismatch is one of the leading sources of dissatisfaction, spending time on this decision before the operating room pays off.

Prostheses in Children and Teenagers

Testicular prostheses are not just for adults. Boys born without one or both testes, or who lose a testicle to torsion or cancer in childhood, can receive implants. One recommendation in the pediatric literature is that the first prosthesis should ideally be placed between ages one and three, or within a year of testicle removal, to normalize the scrotal appearance early in the child’s development.¹⁴

There is a catch: a small child’s body grows, but a silicone implant does not. A prosthesis placed in a toddler will eventually be too small for an adolescent’s body. This means a planned exchange surgery is part of the deal. In a series of 13 patients aged 5 to 18 who received implants at one center, three later had the original prosthesis swapped for an adult-sized one.¹⁵ The timing and number of exchanges depend on when the initial implant goes in and how quickly the child grows.

The surgical approach also differs slightly in younger patients. Accessing the scrotum from above, through the inguinal region, tends to produce better long-term results in boys compared to a direct scrotal incision.¹⁶ The reasoning relates to the smaller scrotal anatomy in children and the need to secure the implant in a position where it is less likely to migrate as the child grows.

Testicular Prostheses in Gender-Affirming Surgery

Testicular implants play a distinct role in transmasculine gender-affirming surgery. After scrotoplasty, the surgical creation of a scrotum, testicular prostheses can be inserted to give the neoscrotum a natural appearance and feel. The context here is different from cancer-related reconstruction: the tissue receiving the implant is a surgical graft rather than native scrotal skin, which changes the risk profile.

Prosthesis placement after scrotoplasty is typically performed as a separate, staged procedure at least six months after the scrotum has healed. Immediate placement during the initial surgery is sometimes done, but waiting allows the tissue to stabilize and reduces wound complications.¹⁷ There has been a recent trend toward using smaller, lighter implants in this population, and for good reason. Explantation rates are significantly lower with smaller prostheses.

Complication rates in gender-affirming cases run higher than in orchiectomy patients. In one cohort of 116 implants placed after transmasculine surgery, 12% required removal. The most common reason was erosion of the prosthesis through the tissue. About 10% of patients noticed the implant had migrated from its original position, though only a fraction of those needed reoperation. Smoking history increased the risk of explantation.¹⁸ In a narrative review, infection rates after gender-affirming prosthesis placement ranged from 3% to 11%, and extrusion rates from 7% to 14%. Despite these numbers, about 70% of patients who had an implant removed chose to have a replacement put in.¹⁹ That speaks to how important the implant is to these patients’ sense of bodily wholeness.

How Long They Last

Testicular prostheses are designed to be permanent, and most do last a long time. A long-term follow-up study of patients with differences of sex development who received implants found a median follow-up of about 15 years. Short-term complications were rare, with only one patient out of 27 procedures requiring reoperation for bleeding shortly after surgery. Over the full follow-up period, prosthesis rupture was diagnosed in two patients, at roughly 10.5 and 26 years after placement. Both were replaced. At last follow-up, every patient still had a prosthesis in place.²⁰

Rupture after a decade or more is not common, but it is worth knowing about. With saline-filled implants, a rupture means the shell breaks and the saline leaks into the body, where it is harmlessly absorbed. The visible result is a deflated, visibly smaller scrotum, which prompts the patient to seek replacement. With solid silicone, rupture is less of a concern because the material maintains its shape even if the shell is compromised. Neither scenario is dangerous, but both require a second surgery if the patient wants to maintain the prosthetic appearance.

What Happens Inside the Body

Any foreign object implanted in the body triggers an immune response. With silicone prostheses, the surrounding tissue forms a fibrous capsule around the implant, much like what happens with breast implants. A histological study of capsules formed around both breast and testicular silicone implants found chronic inflammatory features: T-cell and macrophage reactions, foreign body giant cells, and granulomas within dense fibrous connective tissue.²¹

This capsule formation is the body doing exactly what it is supposed to do when it encounters something it cannot absorb or break down. In most patients, the capsule stabilizes and causes no symptoms. In some, excessive fibrosis can make the implant feel harder over time or contribute to discomfort. Current research is exploring surface coatings that reduce this fibrotic response. In an animal model, a silicone prosthesis modified with an anti-inflammatory coating developed a capsule roughly a third as thick as an uncoated control implant, with less macrophage infiltration and less collagen buildup.²²

What a Prosthesis Cannot Do

A testicular prosthesis is purely cosmetic and structural. It does not produce testosterone, and it does not make sperm. If you have lost one testicle, the remaining one typically compensates by producing enough testosterone and sperm on its own. If both testicles are absent, you will need testosterone replacement therapy regardless of whether prostheses are placed. The implant does nothing to change that equation.

That said, researchers are investigating the idea of functional prostheses that could slowly release testosterone within the body. The concept would reduce or eliminate the need for injections, gels, or patches in patients who require hormone replacement. This remains experimental, with no products currently available for clinical use.²³ If such a device ever reaches the market, it would represent a genuine shift in what testicular prostheses are for, moving them from purely cosmetic to medically functional.

Prostheses for Pets

Testicular prostheses are not limited to humans. Neuticles, a brand of prosthetic testicles for dogs and cats, have been commercially available since the mid-1990s and have sold in large numbers. The premise is straightforward: some pet owners feel uncomfortable with the altered appearance of their neutered animal and want to restore a natural look. Research into the veterinary application has focused on where best to place the implant. In a study of beagle dogs comparing two implantation sites, prostheses placed under the outer testicular membrane showed better mobility and feel compared to those placed deeper, and the surrounding tissue showed less chronic inflammation.²⁴ None of the animals in that study showed rejection or infection.

The veterinary market for testicular prostheses has been, depending on your perspective, either a practical solution to owner concerns or a curiosity of modern pet culture. Either way, the devices appear to be well-tolerated by animals and have arguably helped normalize the concept of testicular prostheses more broadly, making a topic that might otherwise carry stigma feel a little more ordinary.

Gaps in the Evidence

One persistent problem in this field is the lack of standardized ways to measure outcomes. The systematic review of patient-reported outcomes found that while satisfaction numbers are consistently high, the tools used to measure satisfaction vary widely from study to study. There are no widely validated, prosthesis-specific questionnaires in common use, which makes it hard to compare results across centers or draw firm conclusions about which techniques and materials produce the best outcomes.²⁵ Until the field settles on standard outcome measures, the evidence will remain somewhat fragmented, even if the overall picture is encouraging.