The choice is not the patient’s to make alone, and it comes second. First a prescriber has to establish that hypogonadism exists. Only then does route enter the picture, weighed against which product is available, what the label permits, personal history including fertility plans and red cell counts, and how well someone tolerates the process.
Medically reviewed by Dr. Judson Brandeis, MD, Urology
The diagnosis comes before the route
Every US label in this class opens the same way. Before starting therapy, serum testosterone should be measured in the morning on at least two separate days, and both results should fall below the normal range. A single low reading taken in the afternoon after a bad week of sleep is not a diagnosis. Symptoms are assessed alongside those numbers, and secondary causes get ruled out.
The labels also carry a limitation of use worth reading directly: safety and efficacy in men with age-related hypogonadism have not been established. Testosterone therapy is treatment for a diagnosed condition. It is not a wellness product, and the professional guidelines are consistent that it should not be started on the basis of vague fatigue alone.
What the label allows narrows the field first
Only one injectable testosterone product in the United States is approved for subcutaneous administration: the testosterone enanthate auto-injector sold as Xyosted, which its label describes as being for subcutaneous use and directs prescribers to keep away from intramuscular and intravascular administration. Testosterone cypionate injection is labeled for intramuscular use only. Generic enanthate solution carries the same intramuscular route, and testosterone undecanoate is intramuscular only and is dispensed under a restricted program.
Subcutaneous administration of a cypionate vial therefore happens off label. That is legal and it is done, but the distinction matters when weighing an option: one path has an approved route on an approved device, the other is clinical practice built on top of a label that says something different.
Medical history that genuinely moves the decision
A few pieces of history carry real weight. A history of high hematocrit or polycythemia is one, because exogenous testosterone increases red cell production and comparative work has found differences between delivery formats on that measure. Anticoagulation and bleeding disorders come up as well, since bleeding risk is one of the factors a prescriber weighs when settling on a route. Prostate history, sleep apnea, uncontrolled hypertension, and cardiovascular history all appear in the warnings sections of these labels and shape whether therapy starts at all.
Fertility deserves its own line. Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis, lowers intratesticular testosterone, and impairs sperm production, and a review in Asian Journal of Andrology describes azoospermia as a well-documented consequence that may be temporary or permanent depending on the individual and the duration of use. Anyone who wants children should raise it before the first prescription, not after.
Access and practicality are legitimate inputs
Route affects how the therapy fits into a life. A crossover pilot study published in the American Journal of Health-System Pharmacy reported that participants who moved from intramuscular to subcutaneous administration described less pre-injection anxiety and less pain, though the sample was small and variability between people was wide. Preference data like that is soft evidence, but adherence is the outcome that decides whether any of this works.
Access also depends on where someone starts looking. The direct-to-consumer field for men’s health has widened, and the providers in it are genuinely separate businesses with their own prescribers and formularies. Ro, Hims and Hers, Henry Meds, and HealthRX, which runs its own testosterone replacement therapy program, each set their own rules on which products they stock and how a first visit is handled, so the starting point shapes which route is even on the table.
Supply matters too. Generic vials are widely stocked. A branded device may need prior authorization. The undecanoate product requires attendance at a clinic with an observation period after each administration, which is impractical for some schedules and a relief for people who would rather not handle it themselves.
Where a program fits into the choice
Route is one of several things a service decides on a patient’s behalf, and it is rarely stated on a pricing page. Providers ranging from hospital endocrinology and urology clinics to men’s health services such as Hone Health, Marek Health, Maximus, and formblends.com differ in which products they can dispense, how often they order labs, and whether they will support a route that is off label for the product involved. Asking which specific product arrives, and what the plan is if it does not suit, separates programs faster than comparing marketing copy.
| Input | Who owns it | How it affects route |
|---|---|---|
| Confirmed morning testosterone results | Prescriber | Decides whether therapy starts at all |
| Labeled route of the available product | Set by the label | Only one injectable is approved subcutaneously |
| Hematocrit and polycythemia history | Prescriber | Influences product and monitoring intensity |
| Fertility intentions | Patient, raised early | May change the whole treatment plan |
| Tolerance of the procedure | Patient | Drives adherence, so it is worth voicing |
| Insurance and stocking | Plan and pharmacy | Often decides which product is realistic |
Two things that should never enter the decision
Athletic performance is the first. Testosterone is prohibited in competitive sport under the World Anti-Doping Code, and a therapeutic prescription does not by itself resolve that for a tested athlete. Anyone competing under an anti-doping program needs to work through the exemption process rather than assume a prescription covers it.
Sourcing outside the pharmacy is the second. Testosterone is a Schedule III controlled substance under the Controlled Substances Act, which its labels state directly. Product obtained without a prescription has no verified identity or sterility, and the pattern of harm from non-prescribed androgen use is well described in the clinical literature. The FDA maintains guidance on evaluating online pharmacies precisely because this market attracts unregulated sellers.
Frequently asked questions
Can someone request a specific route?
Raising a preference is reasonable and prescribers generally want to hear it, since tolerance affects whether treatment continues. The decision still belongs to the prescriber, because it depends on which product is available, what its label permits, and what the individual history supports.
Does one route work better for absorption?
Comparative work suggests total testosterone exposure ends up broadly similar between the two, with differences appearing in secondary measures rather than in whether the hormone gets absorbed. The studies are modest in size, so the honest answer is that route is more about tolerability and product access than potency.
Is the training different for each route?
Yes, and it comes from the prescriber or the dispensing pharmacist rather than from written material or video. The technique, the preparation, and the handling differ between a vial product and a single-use device, and a demonstration is the appropriate way to learn either one.
What if fertility becomes a priority later?
Raise it immediately. Recovery of sperm production after stopping exogenous testosterone varies, and published work has found that age and how long therapy ran predict how long return takes. Options exist, but they are managed by a clinician and they work better when the conversation happens early.
Should a high hematocrit change the route?
It changes the monitoring plan for certain, and it may change the product. Elevated red cell mass is the adverse effect most consistently tracked with injectable testosterone, and how a prescriber responds depends on the reading, the trend, and the person’s other risk factors.
