Testosterone enanthate is most commonly injected once a week, though some people inject every two weeks or even twice weekly depending on their prescribed dose and how their body responds. The Endocrine Society guidelines recommend either 75 to 100 mg weekly or 150 to 200 mg every two weeks for testosterone replacement therapy. Weekly injections are generally preferred because they produce more stable hormone levels and fewer side effects.
Why Weekly Injections Are the Standard
Testosterone enanthate has a half-life of about 7 to 9 days, meaning half the dose is still active in your body roughly a week after injection. This makes once-weekly dosing a natural fit. After a single shot, testosterone levels rise into a peak (typically within about 12 hours for subcutaneous injections) and then gradually decline over the following days.
Clinical data confirms that 100 mg injected weekly keeps serum testosterone within the normal therapeutic range by the time the next dose is due. A 200 mg dose given every two weeks can also maintain adequate levels, but the peaks and troughs are significantly wider. You get a larger spike right after the injection and a deeper dip before the next one. That roller coaster is why many prescribers and patients prefer the weekly schedule even though it means more injections.
Every Two Weeks: When It’s Used and Why It’s Less Ideal
Injecting 150 to 200 mg every two weeks is still a recognized protocol and appears in the Endocrine Society guidelines as an option. Some people choose it simply because fewer injections feel more manageable. In practice, though, the wider gap between doses causes testosterone to drop into the low range (sometimes below therapeutic levels) in the final days before the next shot. That dip can show up as fatigue, irritability, low mood, or decreased energy, essentially recreating some of the symptoms therapy is meant to fix.
Less frequent schedules with even higher doses, such as 300 mg every three weeks or 400 mg every four weeks, have been studied. These protocols tend to produce supraphysiological peaks early on followed by inadequate levels later in the cycle, making them poor choices for steady hormone replacement.
Twice-Weekly Injections for Smoother Levels
Some people split their weekly dose into two smaller injections, for example 50 mg on Monday and 50 mg on Thursday instead of 100 mg once a week. This approach narrows the gap between peak and trough levels even further. For people who notice mood swings, energy dips, or other symptoms tied to fluctuating hormones, twice-weekly dosing can make a noticeable difference.
Twice-weekly protocols also reduce the total spike after each injection. That matters because high peaks drive more conversion of testosterone into estrogen through a process called aromatization. Keeping peaks lower may help reduce estrogen-related side effects like water retention or breast tissue sensitivity. It can also help keep red blood cell production (hematocrit) more stable, since large testosterone spikes stimulate more red blood cell growth. If hematocrit rises above 54%, therapy typically needs to be paused due to increased clotting risk.
Intramuscular vs. Subcutaneous Injections
Testosterone enanthate is traditionally injected into muscle (intramuscular, or IM), usually in the thigh or glute. IM injections work well but can be uncomfortable, and many people find it difficult to self-inject, sometimes needing help from a family member.
Subcutaneous injection (into the fat layer just under the skin, typically in the abdomen or thigh) is an increasingly popular alternative. Research shows that subcutaneous injections at the same doses produce comparable blood levels and similar pharmacokinetics to intramuscular shots. They’re also easier to do yourself and generally less painful. The FDA-approved subcutaneous form (Xyosted) is dosed at 50 to 100 mg weekly, and most patients using this route follow a weekly schedule.
Typical Dose Ranges
For standard testosterone replacement, weekly doses typically fall between 50 and 150 mg. The most common starting point is 100 mg per week. In one study of 63 patients receiving weekly subcutaneous testosterone, the majority achieved target testosterone levels (348 to 1,197 ng/dL) at doses of 50 to 80 mg per week. A smaller number needed 100 or 150 mg.
Your ideal dose depends on your bloodwork. The goal is generally to keep your mid-cycle or trough testosterone between 350 and 600 ng/dL. If your levels land above 600 ng/dL at the midpoint between injections, your dose or frequency may need to be adjusted downward. If they fall below 350 ng/dL, you may need a higher dose or more frequent injections. Doses of 300 mg per week and above are associated with a high incidence of adverse effects and are not used in standard replacement therapy.
When to Get Blood Work
The timing of your blood draw matters a lot for accurate monitoring. For testosterone enanthate, bloodwork should be done either at trough (right before your next scheduled injection) or at the midpoint between injections. If you inject every Monday, a trough draw would happen Monday morning before your shot. A midpoint draw on a two-week cycle would fall at the one-week mark.
Beyond testosterone levels, your prescriber will periodically check hematocrit (red blood cell concentration) and estradiol (estrogen). Elevated hematocrit is one of the more common complications of testosterone therapy. Estrogen can also climb because testosterone naturally converts to estradiol in the body, and higher, less frequent doses amplify this conversion. Regular lab monitoring, typically every 3 to 6 months during the first year and at least annually after that, helps catch these issues early.
Finding Your Optimal Schedule
The “right” injection frequency is the one that keeps your testosterone in a healthy range while minimizing symptoms between doses. Start with whatever your prescriber recommends, which will almost always be weekly. Pay attention to how you feel in the days after injection compared to the day before your next one. If you notice a clear pattern of energy or mood dropping right before each shot, splitting your dose into two injections per week is a straightforward adjustment to discuss.
Consistency matters more than perfection. Pick a schedule you can stick with. Missing or delaying injections creates the same kind of hormonal instability that less frequent dosing does. Many people find that setting a recurring reminder for the same day(s) each week turns injections into a routine that’s easy to maintain long term.