Short answer: In the 1-year Xyosted study (150 men), the most common reactions were hematocrit increased (14.0%), hypertension (12.7%), PSA increased (12.0%), injection site bruising (6.7%) and headache (5.3%). These studies had no placebo group. Across both studies, 12.7% of men had injection-site reactions and 4.2% had hematocrit reach 55% or more. The current label has no boxed warning.
What Xyosted is approved for: Xyosted is approved as testosterone replacement therapy in adult males with low or absent natural testosterone due to primary hypogonadism (testicular failure) or hypogonadotropic hypogonadism (a pituitary or hypothalamus cause). The label says safety and efficacy have not been established in men with "age-related hypogonadism" or in males under 18 (section 1).
Source
XYOSTED (testosterone enanthate) injection, for subcutaneous use, prescribing information and Medication Guide. Antares Pharma. DailyMed, version published April 27, 2026. DailyMed setid 8a3d204c-be26-49e0-8599-0ac12a272e81
No. The current Xyosted label has no boxed warning.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Xyosted.
| Preferred Term | Overall (N=150) n (%) |
|---|---|
| Hematocrit increased | 21 (14.0) |
| Hypertension | 19 (12.7) |
| Prostatic specific antigen (PSA) increased | 18 (12.0) |
| Injection site bruising | 10 (6.7) |
| Headache | 8 (5.3) |
| Back pain | 5 (3.3) |
| Blood creatine phosphokinase increased | 5 (3.3) |
| Injection site hemorrhage | 5 (3.3) |
| Acne | 4 (2.7) |
| Blood testosterone increased | 4 (2.7) |
| Cough | 4 (2.7) |
| Edema peripheral | 4 (2.7) |
| Injection site erythema | 4 (2.7) |
| Prostatitis | 4 (2.7) |
| Urinary tract infection | 4 (2.7) |
One-year open study of 150 men. All started on 75 mg weekly and were titrated to 50 mg or 100 mg weekly as needed. There was no placebo group.
| Preferred Term | Overall (N = 133) n (%) |
|---|---|
| Hematocrit increased | 11 (8.3) |
| Injection site hemorrhage | 8 (6.0) |
| Blood creatine phosphokinase increased | 5 (3.8) |
| Injection site bruising | 5 (3.8) |
| Prostatitis | 4 (3.0) |
| Prostatic specific antigen (PSA) increased | 4 (3.0) |
| Urinary tract infection | 4 (3.0) |
| Fatigue | 3 (2.3) |
| Hypertension | 3 (2.3) |
| Insomnia | 3 (2.3) |
| Nausea | 3 (2.3) |
Six-month study of 133 men, which also measured 24-hour blood pressure. There was no placebo group.
Blood pressure: in 62 men with usable 24-hour readings, systolic rose by an average of 3.9 mm Hg and diastolic by 1.5 mm Hg from baseline to week 12. 10% of men in the 1-year study were started on, or had changes to, blood pressure medicine.
Red blood cells: hematocrit reached 55% or more in 12 of 283 men (4.2%). Mean hematocrit rose 3.8% at 6 months and 5.4% at 1 year; mean hemoglobin rose 1.0 g/dL at 6 months and 1.1 g/dL at 1 year.
Injection-site reactions (bruising, bleeding, redness, hardness) were reported in 36 of 283 men (12.7%). No one stopped Xyosted because of them.
Depression leading to stopping treatment was reported in 2 of 283 men, and suicide attempts (one complete, one incomplete) in 2 more: 4 men in all, 1.4%.
PSA rises (an increase of at least 1.4 ng/mL from baseline, or PSA above 4 ng/mL) led 4.6% of the 283 men to stop treatment.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Polycythemia (high red blood cells). Hematocrit is checked before starting and about every 3 months on Xyosted. If it is high, Xyosted is stopped until it comes down; if it rises again after restarting, Xyosted is stopped for good.
Blood clots. Deep vein thrombosis and pulmonary embolism have been reported with testosterone products. In the TRAVERSE study of a testosterone gel, clots occurred in 1.7% vs 1.2% on placebo. If a clot is suspected, Xyosted is stopped.
Enlarged prostate and prostate cancer. Men with an enlarged prostate (BPH) may see their symptoms worsen, and androgens may raise prostate cancer risk. The label says to check for prostate cancer before and during treatment.
Blood pressure increases. Xyosted can raise blood pressure: by an average of 3.9/1.5 mm Hg after 12 weeks in trials. Blood pressure is checked periodically, and Xyosted is not recommended with uncontrolled high blood pressure.
Abuse and testosterone level checks. Testosterone has been abused at higher-than-approved doses, often with other anabolic steroids, which can cause serious heart and mental health problems. If abuse is suspected, serum testosterone is checked.
Not for use in women. Xyosted is not indicated for women because of a lack of controlled studies and possible masculinizing effects.
Sperm production. Large doses of testosterone can suppress sperm production through feedback on the pituitary, which could lower sperm count.
Liver effects. Long use of high-dose oral 17-alpha-alkyl androgens has been linked to serious liver problems. The label notes long-term intramuscular testosterone enanthate has produced multiple liver adenomas; Xyosted is not known to cause these effects. If liver signs such as jaundice appear, Xyosted is stopped while they are checked.
Edema (fluid retention). Androgens can cause the body to hold salt and water. Swelling, with or without heart failure, can be serious in people with heart, kidney or liver disease.
Gynecomastia. Breast enlargement may develop and may persist.
Sleep apnea. Testosterone may worsen sleep apnea, especially with obesity or chronic lung disease.
Lipid changes. Blood fats can change, which may require a change in cholesterol medicine or stopping testosterone. Lipids are checked periodically, especially after starting.
High calcium. In cancer patients at risk of high calcium, Xyosted is used with caution and calcium is checked regularly.
Thyroid lab values. Androgens can lower thyroxine-binding globulin and total T4 on lab tests, but free thyroid hormone stays the same and there is no sign of thyroid disease.
Depression and suicide. Depression and suicidal thoughts and behavior, including completed suicide, occurred in Xyosted trials. The label says to seek medical attention for new or worse depression, anxiety, mood changes or suicidal thoughts.
From the Medication Guide that comes with Xyosted:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.