Testosterone replacement therapy (TRT) can be taken as injections, topical gels, implanted pellets, or oral capsules. Injections are the most common method, but each option has a different routine, frequency, and set of trade-offs. Here’s what each method actually looks like in practice so you know what to expect.
Injections: The Most Common Method
Most people on TRT use injectable testosterone, either into a muscle (intramuscular) or just under the skin (subcutaneous). Intramuscular shots typically go into the buttock, the outer thigh, or the deltoid muscle of the upper arm. Subcutaneous injections are given into the fatty tissue of the stomach area, similar to how insulin is injected.
Dosing frequency depends on the formulation your provider prescribes, but weekly injections are standard for many protocols. Some people split their dose into two smaller injections per week to keep levels more stable and reduce the peaks and valleys that can affect mood and energy.
How to Give Yourself an Injection
If you’re self-injecting, the process follows the same basic steps each time. Start by washing your hands thoroughly. Wipe the rubber stopper on the vial with an alcohol swab before drawing up your dose. Use a new, sterile needle and syringe every time. Many people use a thicker needle to draw the oil out of the vial, then swap to a thinner needle for the actual injection, since testosterone is suspended in thick oil that draws slowly.
Clean the injection site with alcohol and let it dry. For intramuscular shots, insert the needle at a 90-degree angle. For subcutaneous shots, you may pinch a fold of skin and insert at a shallower angle. Push the plunger slowly, withdraw the needle, and apply light pressure with a cotton ball or gauze.
Rotate your injection sites each time. If you inject into your left thigh one week, use your right thigh the next. This prevents scar tissue from building up in one spot, which can make future injections more painful and less effective at absorbing the medication.
Storing Your Testosterone
Keep your vials at room temperature, ideally between 68°F and 77°F. Testosterone cypionate, one of the most commonly prescribed forms, is prone to crystallizing if it gets too cold. If you notice crystals in the vial, warming it gently in your hands and shaking it will dissolve them. Don’t microwave it or use hot water.
Topical Gels and Solutions
Testosterone gel is applied directly to your skin, usually once daily in the morning. Common application sites include the upper arms, shoulders, or inner thighs, depending on the product. You should never apply it to your penis, scrotum, or any skin that has cuts or irritation.
After applying the gel, let it dry for several minutes before putting on clothing that fully covers the area. This step matters because testosterone gel transfers easily through skin-to-skin contact. If a partner, child, or pet touches the area before it’s been washed off, they can absorb the hormone themselves, which can cause serious side effects, particularly in women and children. Always wash your hands with soap and water immediately after application. If you expect close physical contact with someone, wash the application area thoroughly first.
One detail that surprises many people: testosterone gel is flammable until it dries completely. Avoid open flames and don’t smoke while applying it or immediately afterward.
Gels offer the advantage of steady daily dosing without needles. The trade-off is the transfer risk and the daily routine, which some people find inconvenient compared to a weekly injection.
Implanted Pellets
Testosterone pellets are small, rice-grain-sized implants placed under the skin, typically in the upper buttock or hip area. They release testosterone slowly over time and are replaced roughly every three months, though some people go longer between insertions.
The procedure is done in a clinic and takes about 10 to 15 minutes. You lie on your side or stomach while the area is cleaned and numbed with a local anesthetic. The provider makes a tiny incision (about half an inch), inserts a small tube about the size of a coffee stirrer into the fat layer between your skin and muscle, and pushes the pellets through it. The incision is closed with tape and covered with gauze.
The appeal of pellets is convenience. Once they’re in, you don’t think about your TRT for months. The downside is that if you have side effects or need a dose adjustment, you can’t simply stop taking them the way you can with injections or gel. They’re already in your body and will continue releasing testosterone until they’re absorbed.
Oral Testosterone
Oral testosterone capsules are a newer option that avoids needles and skin transfer concerns entirely. The key rule with oral testosterone is simple: take it with food. The medication needs dietary fat to be absorbed properly. Taking it on an empty stomach significantly reduces how much your body actually uses.
Older forms of oral testosterone were linked to liver damage, and the American Urological Association still recommends against a specific older class of oral testosterone (alkylated formulations) for this reason. Newer oral formulations use a different chemical structure that bypasses the liver, making them safer for long-term use.
What to Expect After Starting
TRT doesn’t produce overnight results. Changes unfold in a predictable sequence over weeks and months, and knowing the timeline helps set realistic expectations.
In the first one to four weeks, many people notice early shifts in mood, motivation, and general sense of well-being as testosterone levels begin rising. Some report increased sexual interest during this window, though for others libido takes longer to change. Mental fog and fatigue often start lifting in this early phase.
Between months one and three, mood improvements tend to become more consistent. People commonly describe clearer thinking, reduced mental fatigue, and more emotional stability. Depressive symptoms tied specifically to low testosterone (rather than clinical depression from other causes) often show meaningful improvement by the three-month mark. Libido continues developing as levels stabilize. Lean muscle mass and strength gains typically start becoming visible somewhere between weeks four and twelve, assuming you’re physically active.
Months three through six is when body composition changes become most noticeable. Fat reduction and muscle gains that started earlier continue to build. People who maintain a consistent exercise routine during this period report the most significant physical changes.
Blood Work and Ongoing Monitoring
Starting TRT isn’t a one-time decision. It requires regular blood work, especially in the first year. Before you begin, your provider will check baseline levels including your red blood cell concentration (hematocrit) and, if you’re over 40, a PSA test to screen for prostate issues.
After starting treatment, expect blood draws at three months and six months to recheck those same markers. If your red blood cell count climbs too high, specifically above 50%, your provider may pause or adjust treatment, since thickened blood increases the risk of clots. Once your levels are stable, annual testing is typically sufficient.
Two important safety notes: TRT should not be started within three to six months of a cardiovascular event like a heart attack or stroke. And if you’re trying to conceive, exogenous testosterone will suppress your sperm production, often dramatically. It’s not a reliable form of birth control, but it can make conception very difficult or impossible while you’re on it.
Choosing the Right Method
Your choice of delivery method comes down to lifestyle, comfort with needles, and how much daily maintenance you’re willing to manage. Injections offer the most flexibility in dosing and are the least expensive option for most people, but they require a weekly routine and comfort with self-injection. Gels are painless and maintain steady levels but demand daily application and careful precautions around others. Pellets are the most hands-off option but require a minor in-office procedure several times a year and don’t allow quick dose changes. Oral capsules are the simplest daily routine but must be taken with meals and are newer to the market, meaning long-term data is still accumulating.
Most providers will start you on injections or gel and adjust from there based on how your body responds, how your blood work looks, and what fits your life. The “best” method is whichever one you’ll use consistently.