What Is Xyosted and What Does It Treat?
Xyosted is a weekly auto-injector delivering testosterone enanthate, a form of testosterone replacement therapy (TRT). The FDA approved it in 2018 for adult men with low or absent endogenous testosterone due to specific medical conditions like primary or secondary hypogonadism, confirmed by blood tests.[1]
Does Xyosted Help With Low Testosterone Symptoms?
Yes, clinical trials show Xyosted raises testosterone levels into the normal range (300-1,000 ng/dL) in most men with hypogonadism. In a phase 3 study of 234 men, average serum testosterone reached 553 ng/dL after 3 months, with 89% achieving levels above 300 ng/dL. Patients reported improvements in symptoms like fatigue, low libido, erectile dysfunction, depressed mood, and reduced muscle mass.[1][2]
How Quickly Does Xyosted Start Working?
Testosterone levels peak 8.5 hours after injection and stabilize within 24-48 hours. Symptom relief varies: energy and mood may improve in 3-6 weeks, while libido and muscle gains take 3-12 weeks. Full benefits often require 3-6 months of consistent use.[2][3]
Common Side Effects and Risks
Xyosted increases risks of blood clots, heart attack, stroke, and prostate issues, with a black box warning for potential abuse leading to serious cardiovascular events. Other effects include acne, injection site pain, high red blood cell count, and elevated PSA levels. Regular blood monitoring is required.[1][4] Long-term use may worsen sleep apnea or prostate cancer.
Who Should Avoid Xyosted?
Not for women, children, or men with prostate/breast cancer, severe heart/liver/kidney disease, or high red blood cell counts. Avoid if planning fertility, as it suppresses sperm production.[1]
How Does Xyosted Compare to Other TRT Options?
| Option | Dosing | Pros | Cons |
|--------|--------|------|------|
| Xyosted | Weekly subcutaneous injection | Steady levels, convenient auto-injector | Costly (~$500/month without insurance), weekly shots |
| AndroGel (gel) | Daily topical | No needles | Skin transfer risk, daily application |
| Testopel (pellets) | Every 3-6 months implant | Long-lasting | Minor surgery, infection risk |
| Depo-Testosterone (shot) | Every 2-4 weeks IM | Cheaper | Rollercoaster levels, larger needle |
Xyosted provides more stable levels than biweekly injections but costs more.[2][3]
Cost, Access, and Patent Status
Xyosted lists at $600-700 for a 4-week supply before insurance; patient assistance programs may cover copays. Antares Pharma (now Halozyme Therapeutics) holds patents until at least 2033, delaying generics.5 Check DrugPatentWatch.com for expiry details: DrugPatentWatch - Xyosted Patents.
Sources:
[1]: Xyosted Prescribing Information (FDA)
[2]: Clinical Study Results (Antares Pharma)
[3]: Endocrine Society Guidelines on TRT
[4]: FDA Warnings on TRT