TRT Delivery Methods Compared: Injections To Pellets

TRT delivery methods are the routes used to give testosterone replacement therapy: injections into muscle or under the skin, topical gels, and small pellets placed beneath the skin. Each route enters the bloodstream differently. That difference changes dosing frequency, how steady hormone levels stay, the side effect pattern, and how much daily effort the method takes. No single route is right for every man.

Route matters as much as the prescription itself. Most men reach this decision after a provider evaluation through telehealth hormone care, where several routes become available once testosterone deficiency is confirmed by labs and symptoms. The American Urological Association notes that any approved formulation can reach mid-normal testosterone levels when dosed correctly, so the decision rests on patient preference, pharmacokinetics, and treatment burden (Mulhall et al., 2018).

What Is TRT and How Is It Delivered?

Testosterone replacement therapy is a prescription treatment used to raise testosterone in men with confirmed low levels, a condition called hypogonadism. It reaches the body four main ways: intramuscular injection, subcutaneous injection, topical gel, and implanted pellet. The aim is steady testosterone in the normal range, set by lab results and provider evaluation rather than a fixed dose for everyone.

Low testosterone may show up as fatigue, reduced libido, loss of muscle mass, low mood, or poor concentration. A low number alone is not enough to act on. Confirming low testosterone pairs a low lab value with symptoms, which is why testosterone therapy options begin with testing, not a prescription. Men who want the basics first often read how testosterone therapy works before settling on a route.

How Testosterone Injections Work

Testosterone injections deliver the hormone into muscle (intramuscular) or the fat layer under the skin (subcutaneous), usually weekly or twice weekly. They are the longest-established route and generally cost less than gels or pellets.

The old complaint that injections always cause sharp peaks and crashes is less of a concern today. More frequent dosing and the subcutaneous route can smooth levels out, and subcutaneous injection has become more common for that reason.

Injections carry one clear tradeoff. They are associated with higher red blood cell levels than other routes. A 2025 systematic review found injectable forms were associated with a greater rise in red blood cell levels than pellet and topical forms (Liu et al., 2025). That risk is managed with monitoring and, when needed, a dose change. Injections can also suppress sperm production, so men weighing fertility during testosterone therapy should raise it with a provider before starting.

Testosterone Gels and Daily Application

Testosterone gels are applied to the skin once a day, usually on the shoulders or upper arms, and absorbed into the bloodstream. They hold levels steady from day to day and skip needles, which suits men who dislike injections.

The catch is transfer. Testosterone can pass to other people through skin contact, and the FDA requires a boxed warning because secondary exposure has been reported to cause masculinizing effects (virilization) in children and women (FDA, 2013). Washing the area and covering it with clothing lowers that risk. Absorption varies between people, the skin must be clean and dry, and gels often cost more than injections over time. For a closer look at topical versus injectable routes, Marek compares creams and injections in detail.

Testosterone Pellets and Long-Acting Dosing

Testosterone pellets are implanted under the skin during a short in-office procedure and release the hormone over three to six months. The draw is convenience: no daily gel, no weekly needle, and steady levels in between.

That convenience hides the main drawback. Once pellets are placed, the dose cannot be changed without another procedure to remove them. Pellets can also work their way out of the skin or cause infection at the site. The "set it and forget it" pitch undersells how little control a man has after implantation, and limited adjustability is a commonly reported drawback of this route.

How Do TRT Delivery Methods Compare?

All three routes can reach a healthy testosterone range. They differ mainly in dosing frequency, level stability, how easily the dose changes, and the risk of elevated red blood cell levels. One study comparing hypogonadal men on a single formulation found elevated red blood cell levels were most common with injections, least common with gels, and intermediate with pellets (Pastuszak et al., 2015). The same review noted larger increases in estrogen with injectable testosterone and gels.

Some men switch routes as needs change, starting with injections to gauge response, then moving to pellets for lower maintenance. Switching is routine and handled under provider supervision.

Choosing a TRT Delivery Method With a Provider

The right TRT delivery method depends on lifestyle, comfort with needles, fertility plans, and how a man's body handles each route. No option is better for everyone, only better for a given person after evaluation.

A few questions sharpen the choice. How stable will levels stay between doses? How likely is this route to raise red blood cell levels? Can the route be changed later if it does not fit? Whatever the answer, monitoring stays part of the plan. Clinical guidelines advise against starting therapy when red blood cell levels are already high, and the FDA added blood pressure warnings to all testosterone labels in 2025 after reviewing the TRAVERSE trial (FDA, 2025). Routine follow-up lab work tracks the relevant blood markers across every route.

The Best Route Is the One a Provider Confirms

Across TRT delivery methods, injections offer flexibility and lower cost with a higher chance of elevated red blood cell levels, gels give daily steadiness with a transfer caution, and pellets trade adjustability for convenience. Research supports all three when they are dosed to a normal range and monitored, so the decision belongs with a man and his provider, guided by labs and goals rather than marketing claims.

Disclaimer: This blog post is intended for informational purposes only and should not be considered medical advice. Always consult a healthcare professional before making changes to your health routine.

FAQs

What are the main TRT delivery methods?

The main TRT delivery methods are intramuscular injections, subcutaneous injections, topical gels, and implanted pellets. Each route reaches the bloodstream differently, which affects dosing frequency, level stability, and side effects. The American Urological Association notes that any approved formulation can reach a normal testosterone range when dosed correctly.

Which TRT delivery method costs the least?

Testosterone injections are usually the lowest-cost route and remain the longest-established option. Gels and pellets tend to cost more over time, and pellets carry a higher upfront cost for the implant procedure. Pricing is direct-pay, and HSA or FSA funds may be eligible, so what each plan includes should be confirmed with the provider.

Do testosterone injections affect red blood cell levels more than gels?

Yes. Injectable testosterone is associated with higher red blood cell levels than gels or pellets. In comparisons of hypogonadal men, elevated red blood cell levels were most common with injections and least common with gels. Regular blood monitoring is advised on every route.

Can testosterone gels transfer to other people?

Yes. Testosterone can transfer through skin contact, and the FDA requires a boxed warning on topical gels because secondary exposure has been reported to cause masculinizing effects (virilization) in children and women. Washing the application site and covering it with clothing lowers the risk.

How often are testosterone pellets replaced?

Testosterone pellets are implanted during a short in-office procedure and release the hormone over three to six months. The dose cannot be adjusted between implants without a removal procedure, which is the main tradeoff for the convenience.

Can a man switch between TRT delivery methods?

Yes. Switching between TRT delivery methods is common and done under provider supervision. Some men start with injections to gauge response, then move to pellets or gels for lower maintenance, or change routes to manage side effects such as elevated red blood cell levels.

References

• J Urol. 2018;200(2):423–432

• Blood Adv. 2025;9(9):2108–2118

• Sex Med. 2015;3(3):165–173

• N Engl J Med. 2023;389(2):107–117

• U.S. Food and Drug Administration. Class-Wide Labeling Changes for Testosterone Products. 2025

• U.S. Food and Drug Administration. AndroGel Prescribing Information. 2013