Types of TRT: Injections vs. Gels vs. Pellets vs. Patches

If you’ve been diagnosed with low testosterone, or you’re researching symptoms that point in that direction, one of the first decisions you’ll face is how to take testosterone replacement therapy (TRT). Not whether it works. That part is well-established. The real question is which delivery method fits your body, your routine, and your goals.

Four types of TRT are used in clinical practice today: injections, topical gels, subcutaneous pellets, and transdermal patches. They all deliver the same hormone. The difference is how it enters your bloodstream and how consistently it stays there.

Below, we break down each method with real dosing data, FDA-approved brand names, clinical trade-offs, and the honest pros and cons your provider should be walking you through. If you’re still getting up to speed on what TRT actually is and how it works, start with our complete TRT overview first.

Testosterone Injections

Injections are the most widely prescribed form of TRT in the United States. They deliver testosterone directly into muscle tissue (intramuscular) or just beneath the skin (subcutaneous), where it absorbs into the bloodstream over the following days to weeks.

How Injections Work

A measured dose of testosterone, dissolved in a carrier oil, is injected on a regular schedule. Your body absorbs the hormone gradually as the oil depot breaks down at the injection site. Levels peak within the first few days, then taper until your next dose.

FDA-Approved Injectable Formulations

Three testosterone esters are FDA-approved for injection in the U.S.:

• Testosterone cypionate (Depo-Testosterone): The most commonly prescribed injectable. Dissolved in cottonseed or olive oil. Typically dosed at 100–200 mg per week via intramuscular or subcutaneous injection.
• Testosterone enanthate (Delatestryl, Xyosted): Nearly identical to cypionate in half-life and clinical effect. Xyosted is a pre-filled subcutaneous auto-injector designed for at-home self-administration.
• Testosterone undecanoate (Aveed): A long-acting formulation dosed at 750 mg every 10 weeks after an initial loading phase. Administered only in a clinical setting due to a risk of pulmonary oil microembolism (POME), a rare but serious reaction the FDA requires monitoring for.

Most patients on cypionate or enanthate inject once or twice per week. This frequency keeps serum testosterone levels more stable than the older every-two-week protocols, which tend to produce noticeable peaks and valleys: high energy and mood after injection, then a dip before the next dose.

Pros of Injections

• Precise dose control. Your provider can adjust in small increments (10–20 mg changes) based on lab work, which makes fine-tuning straightforward.
• Consistent absorption. Unlike topical methods, injections aren’t affected by sweat, showering, skin type, or accidental transfer to other people.
• Lowest cost. Testosterone cypionate is available as a generic and is typically the most affordable TRT option, even without insurance.
• Fastest onset. Most patients notice improvements in energy and mood within the first two to four weeks.

Cons of Injections

• Needle requirement. Self-injection is a barrier for some patients, though subcutaneous protocols use small-gauge insulin syringes that most people tolerate well after the first few doses.
• Higher erythrocytosis risk. A study published in the Journal of Clinical Endocrinology & Metabolism found erythrocytosis (hematocrit above 50%) occurred in 66.7% of injection patients compared to 12.8% on gels and 35.1% on pellets. This is why regular blood work, including a complete blood count (CBC), is non-negotiable on injectable TRT.
• Injection site reactions. Occasional soreness, bruising, or minor swelling at the injection site.

Who Injections Work Best For

Patients who want maximum dose flexibility, the lowest ongoing cost, and direct control over their protocol. If you’re comfortable with self-injection (or willing to learn), injections give you and your provider the most room to dial in your levels precisely.

Testosterone Gels

Topical testosterone gels are the second most popular TRT delivery method. Applied daily to the skin, they absorb through the epidermis and enter the bloodstream gradually over several hours.

How Gels Work

You apply a measured amount of gel to the shoulders, upper arms, or abdomen and let it dry for several minutes. The testosterone absorbs through the skin over the next few hours. Because the dose is small and applied daily, gel-based TRT tends to produce relatively stable testosterone levels without the peak-and-trough pattern of less frequent injections.

FDA-Approved Gel Formulations

• AndroGel 1% and 1.62%: Available in metered-dose pumps and single-use packets. Starting dose is typically 50 mg/day (1%) or 40.5 mg/day (1.62%), adjusted based on lab results.
• Testim 1%: Supplied in unit-dose tubes delivering 50 mg of testosterone per tube.
• Vogelxo: Available in tubes, packets, and a pump. Dosing mirrors AndroGel 1%.
• Fortesta 2%: A higher-concentration gel applied to the front and inner thighs. Starting dose is 40 mg/day.

Pros of Gels

• No needles. Application is painless and becomes part of a daily routine.
• Steady levels. Daily dosing produces a relatively flat testosterone curve without significant peaks and troughs.
• Lower erythrocytosis risk. Gel users develop elevated hematocrit at much lower rates than injection patients (12.8% vs. 66.7%).
• Easy to stop. If you experience side effects, testosterone clears your system within 24–48 hours of discontinuing the gel. That’s much faster than waiting for an injection depot to clear or for pellets to dissolve.

Cons of Gels

• Transfer risk. This is the biggest clinical drawback. The FDA requires a boxed warning on all topical testosterone products because of documented cases of secondary exposure to children and female partners through skin-to-skin contact. In clinical testing with AndroGel, 15 minutes of direct skin contact transferred enough testosterone to more than double serum levels in female partners. Covering the application site with clothing reduces but does not eliminate transfer.
• Variable absorption. How much testosterone actually reaches your bloodstream depends on skin thickness, body fat distribution, sweat, and even humidity. Some patients never reach therapeutic levels on gel alone.
• Daily commitment. Miss a day and your levels drop. There’s no “depot” holding residual testosterone the way an injection or pellet does.
• Higher long-term cost. Brand-name gels cost considerably more than generic testosterone cypionate, and insurance coverage varies.
• Lifestyle restrictions. You need to avoid showering, swimming, or heavy sweating for several hours after application to ensure absorption.

Who Gels Work Best For

Patients who cannot tolerate needles and live alone or can reliably avoid skin contact with partners and children for several hours after application. Gels can be a good starting point, but your provider should check levels at four to six weeks to confirm you’re actually absorbing enough to reach the therapeutic range.

Testosterone Pellets

Testosterone pellets are the closest thing TRT has to a “set it and forget it” option. Small, rice-grain-sized cylinders of crystalline testosterone are implanted under the skin during a brief in-office procedure, then dissolve slowly over three to six months.

How Pellets Work

During a minor procedure under local anesthesia, your provider uses a trocar (a small, specialized instrument) to insert six to twelve pellets through a tiny incision, usually in the hip or buttock area. Each pellet weighs approximately 78 mg (containing 75 mg of testosterone). Once implanted, the pellets dissolve gradually, releasing a steady stream of testosterone without any action required from you between insertions.

FDA-Approved Pellet Formulation

• Testopel: The only FDA-approved testosterone pellet in the U.S. Typical dosing ranges from 150 mg to 450 mg (two to six pellets), implanted every three to six months depending on individual metabolism and lab results.

Pros of Pellets

• No daily maintenance. Once inserted, you don’t need to think about your TRT for months.
• Steady hormone levels. Pellets release testosterone at a consistent rate, avoiding the peaks and troughs of injection cycles and the daily fluctuations of gels.
• High patient satisfaction for convenience. In a study published in Translational Andrology and Urology, 64% of pellet users cited ease of use as a primary advantage, compared to 44% of injection users and 43% of gel users.
• No transfer risk. Unlike gels, there is zero risk of transferring testosterone to another person through skin contact.

Cons of Pellets

• No dose adjustments mid-cycle. If your dose is too high or too low, your provider can’t adjust it until the pellets dissolve or until the next insertion. With injections, a dose change takes a week. With pellets, you’re locked in for months.
• Extrusion risk. A small percentage of pellets can work their way back out through the insertion site, particularly within the first month. Historical extrusion rates ranged from 8.5% to 12%, though more recent Testopel data reports rates as low as 0.3%.
• In-office procedure required. Every insertion requires a clinic visit, local anesthesia, and a minor surgical procedure. This limits pellets to patients who live near a provider and can schedule visits every three to six months.
• Infection risk. As with any procedure that breaks the skin, there is a small risk of infection, bleeding, or bruising at the insertion site.
• Higher upfront cost per cycle. The procedure plus pellet cost can exceed the quarterly cost of injectable testosterone, though the gap varies by clinic and insurance.

Who Pellets Work Best For

Patients who travel frequently, dislike daily or weekly routines, or simply want the least hands-on option available. Pellets are also a good fit if you’ve already confirmed your ideal dose on another method and want to simplify. Since adjustments mid-cycle aren’t practical, it helps to already know what your body needs before switching to pellets.

Testosterone Patches

Transdermal testosterone patches deliver a controlled dose of testosterone through the skin over a 24-hour period. Same basic principle as a nicotine patch: a reservoir of medication absorbs gradually through the skin at the application site.

How Patches Work

A patch is applied to clean, dry skin on the back, abdomen, upper arms, or thighs and worn for 24 hours before being replaced. Application sites should be rotated, with at least seven days between applying to the same area to reduce skin irritation.

FDA-Approved Patch Formulation

• Androderm: The primary FDA-approved testosterone patch. Available in 2 mg/day and 4 mg/day systems. The recommended starting dose is one 4 mg/day patch applied nightly. Serum testosterone is checked approximately two weeks after starting, and the dose is adjusted to maintain levels between 400–930 ng/dL.

Important note: Androderm has been discontinued in the United States and may have limited or no availability depending on your pharmacy and region. If patches are your preferred delivery method, discuss current availability with your provider.

Pros of Patches

• No needles, no procedure. Application is as simple as sticking on a patch nightly.
• Steady 24-hour delivery. Because the patch releases testosterone continuously, it mimics the body’s natural diurnal rhythm more closely than most other methods.
• High efficacy when adherent. Clinical data showed up to 92% of patients using Androderm reached normal testosterone levels — one of the highest response rates among TRT formulations.
• No transfer risk (when patch is in place). Unlike gels, the testosterone is contained within the patch system and doesn’t sit on the skin surface.

Cons of Patches

• Skin irritation. This is the most common reason patients discontinue patches. Redness, itching, burning, and even blistering at the application site are reported frequently. Rotating application sites and using topical hydrocortisone after removal can help but doesn’t eliminate the issue for everyone.
• Adhesion problems. Patches can loosen or detach during physical activity, sweating, or showering. In hot and humid climates, adhesion reliability drops further.
• Limited availability. With Androderm’s discontinuation in the U.S., accessing patch-based TRT has become much harder.
• Visible on the body. Unlike gels that absorb invisibly, a patch is a visible appliance that some patients find inconvenient or uncomfortable.
• Limited dose flexibility. Patches come in fixed sizes (2 mg and 4 mg), so fine-tuning your dose is harder compared to injections or gels.

Who Patches Work Best For

In practical terms, patches have become a less common choice because of availability issues and high rates of skin irritation. They may suit patients who can’t use injections and have experienced transfer concerns with gels, but your provider will need to confirm that a patch formulation is still available through your pharmacy before writing the prescription.

Side-by-Side Comparison

	Injections	Gels	Pellets	Patches
FDA-Approved Brands	Depo-Testosterone, Delatestryl, Xyosted, Aveed	AndroGel, Testim, Vogelxo, Fortesta	Testopel	Androderm (discontinued)
Frequency	1–2x/week (cypionate, enanthate) or every 10 weeks (undecanoate)	Daily	Every 3–6 months	Daily (nightly)
Administration	Self-injection (IM or SubQ) or in-clinic for Aveed	Self-applied to skin	In-office minor procedure	Self-applied patch
Dose Adjustability	High — can adjust in 10–20 mg increments	Moderate — can change pump actuations	Low — locked until next insertion	Low — fixed patch sizes
Transfer Risk	None	High (FDA boxed warning)	None	Minimal (when patch is intact)
Skin Irritation	Injection site soreness only	Possible at application site	At insertion site only	Common; most frequent reason for discontinuation
Relative Cost	Lowest (generic cypionate)	Higher (brand-name gels)	Higher (procedure + pellet cost)	Moderate (limited availability)
Erythrocytosis Risk	Highest (66.7%)	Lowest (12.8%)	Moderate (35.1%)	Comparable to gels
Patient Satisfaction	73%	68%	70%	Data limited

Erythrocytosis and satisfaction data sourced from Pastuszak et al., Journal of Clinical Endocrinology & Metabolism, and Kovac et al., Translational Andrology and Urology.

What About Oral Testosterone?

You may have heard about newer oral TRT options. Three oral testosterone undecanoate formulations — Jatenzo, Tlando, and Kyzatrex — are now FDA-approved. These capsules bypass the liver by absorbing through the lymphatic system, which addresses the liver toxicity concerns that kept older oral testosterone formulations off the market for decades.

Oral TRT is still relatively new and long-term data is still accumulating, but for patients who can’t use or don’t want injections, gels, pellets, or patches, it’s worth asking your provider about.

How the TRAVERSE Trial Changed the Conversation

For years, a major concern around TRT was cardiovascular safety. The FDA added a boxed warning to all testosterone products in 2015 citing potential heart risks. That warning shaped prescribing habits for a decade.

Then came the TRAVERSE trial. It was a randomized, placebo-controlled study of 5,246 men with hypogonadism and pre-existing or high risk of cardiovascular disease. Published in the New England Journal of Medicine, TRAVERSE found no increased risk of major adverse cardiovascular events (MACE) in men using testosterone versus placebo over a mean follow-up of 33 months (hazard ratio 0.96; 95% CI, 0.78–1.17). That’s a big study with a clear result.

In February 2025, the FDA responded by removing the cardiovascular boxed warning from testosterone product labeling. The agency did add a new requirement: labeling must now note that all testosterone products can increase blood pressure, based on ambulatory blood pressure monitoring (ABPM) studies conducted post-market.

The cardiovascular risk question, the one that made many providers hesitant to prescribe TRT, now has a definitive, large-scale answer. TRT under proper medical supervision, with regular blood pressure and lab monitoring, is not associated with the cardiac events that earlier, smaller studies suggested.

Choosing the Right Type of TRT

There is no universally “best” type of TRT. The right delivery method depends on your lifestyle, your tolerance for needles, your budget, and how important dose flexibility is. But the most important factor is your lab results and how your provider interprets them.

A few practical starting points:

• If dose precision and cost matter most: Start with injections. Widest dosing range, lowest cost, fastest path to getting your levels where they need to be.
• If needles are a hard no: Gels are the most accessible needle-free option, but you need to manage transfer risk carefully, especially if you live with a partner or children.
• If convenience is your top priority: Pellets eliminate daily and weekly commitments. Just make sure your dose is already well-established before committing to a three-to-six-month cycle you can’t adjust.
• If you want the newest option: Oral formulations like Jatenzo, Tlando, or Kyzatrex may be worth discussing with your provider, though long-term outcome data is still limited.

What matters more than the delivery method is the clinical infrastructure around it. Any type of TRT can go sideways without proper lab monitoring, dose adjustments, and follow-up. That’s where the provider you choose matters as much as the prescription they write.