Comparative Pharmacology
Head-to-head clinical analysis: ANDROID 25 versus TESTIM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ANDROID 25 versus TESTIM.
ANDROID 25 vs TESTIM
Head-to-head clinical comparison of therapeutic indices and safety profiles.
Android 25 contains methyltestosterone, a synthetic androgen that binds to androgen receptors, promoting protein synthesis and anabolic effects. It also inhibits gonadotropin secretion from the pituitary, reducing endogenous testosterone production.
Testosterone replacement therapy; binds to and activates androgen receptors, modulating gene expression leading to male sexual development and maintenance of secondary sexual characteristics.
Hypogonadism in males (primary and secondary)Delayed puberty in malesMetastatic breast cancer in women (as palliative therapy)
Testosterone replacement therapy for adult males with conditions associated with low testosterone (hypogonadism)Off-label: augmentation of sexual function in certain populationsOff-label: treatment of delayed puberty in males
Testosterone 25 mg subcutaneously or intramuscularly every 2 to 4 weeks. Alternatively, 125 mg intramuscularly every 10 days.
Apply 5 g (1 tube) of 1% gel to clean, dry, intact skin of the shoulders, upper arms, or abdomen once daily, preferably in the morning. Dosage may be adjusted to 10 g (2 tubes) depending on clinical response. Apply immediately after opening and avoid bathing or swimming for at least 30 minutes.
None Documented
None Documented
Terminal elimination half-life: 10–100 minutes (testosterone); clinical context: rapid clearance necessitates frequent dosing or use of esters for sustained effect
Terminal elimination half-life of testosterone from serum is approximately 10-100 minutes after intravenous administration, but after transdermal application of Testim, the apparent half-life is longer (around 1-2 hours) due to continued absorption from the skin depot. The half-life of active metabolites (e.g., dihydrotestosterone) is about 2-3 hours.
Primarily hepatic via reduction and oxidation; metabolites include androsterone and etiocholanolone; excreted in urine.
Primarily hepatic via CYP3A4 and other CYPs; metabolites undergo glucuronidation and excretion in urine.
Renal: 90% (as glucuronide and sulfate conjugates, 5–10% unchanged); fecal/biliary: 10%
Testosterone is primarily excreted in urine as glucuronide and sulfate conjugates (approximately 90%), with about 6% excreted in feces via bile. Less than 1% is excreted unchanged.
97–99% (sex hormone-binding globulin and albumin)
Approximately 97-99% bound: mainly to sex hormone-binding globulin (SHBG) (about 40-50%) and albumin (about 50-60%), with a small fraction bound to corticosteroid-binding globulin.
0.3–0.6 L/kg; indicates distribution into lean muscle and sex organs
Volume of distribution (Vd) is approximately 1 L/kg, indicating extensive distribution into tissues. Pseudoequilibrium volume of distribution after transdermal application is about 28 L (for a 70 kg individual), suggesting significant partitioning into muscle and fat.
Oral: <5% (methyltestosterone: ~20–25% due to 17α-alkylation); IM: 100%
Transdermal gel (Testim 1%): Approximately 10% of the applied dose is systemically absorbed; bioavailability is about 9-14% of the applied amount. Oral testosterone has negligible bioavailability (<1%) due to first-pass metabolism.
No dose adjustment required for GFR ≥30 mL/min. For GFR <30 mL/min, consider reducing dose or increasing interval; monitor for fluid retention and hypertension.
No specific dose adjustment required for renal impairment. Use caution in severe renal impairment due to potential for reduced clearance of testosterone metabolites.
Contraindicated in Child-Pugh class B or C cirrhosis. For mild hepatic impairment (Child-Pugh A), start with lower dose (e.g., 12.5 mg every 2 weeks) and titrate based on response and liver function.
Contraindicated in severe hepatic impairment (Child-Pugh class C). In mild to moderate impairment (Child-Pugh class A or B), use with caution; start at lowest dose and monitor serum testosterone levels and hepatic function.
Not recommended for use in pediatric patients (safety and efficacy not established). For male adolescents with hypogonadism, individualize: start at 12.5 mg every 2 weeks and adjust based on testosterone levels and growth.
Not indicated for use in pediatric patients under 18 years of age. Safety and efficacy have not been established.
Start with lower initial dose (e.g., 12.5 mg every 2 weeks); monitor prostate-specific antigen (PSA) and hematocrit frequently. Avoid in patients with prostate cancer or untreated sleep apnea.
No specific dose adjustment recommended solely based on age. However, elderly patients may be more sensitive to androgenic effects; monitor for prostatic hypertrophy, edema, and sleep apnea. Consider lower initial doses (e.g., 5 g daily) and titrate based on clinical response and serum testosterone levels.
WARNING: Androgens are contraindicated in pregnancy due to masculinization of female fetus. Hepatotoxicity, including peliosis hepatis and hepatic neoplasms, has been reported with prolonged use.
Testosterone has been associated with increased risk of cardiovascular events (myocardial infarction, stroke) and venous thromboembolism. Use with caution in patients with cardiovascular disease.
Use with caution in patients with hepatic, renal, or cardiovascular disease; may cause gynecomastia, edema, hypercalcemia, and polycythemia; monitor liver function, lipid profile, and hematocrit periodically; may accelerate bone maturation in children; risk of prostate hypertrophy and urethral obstruction.
Risk of cardiovascular events, venous thromboembolism, erythrocytosis, sleep apnea exacerbation, prostatic hypertrophy, and hepatotoxicity; monitor hematocrit and serum testosterone levels.
Known or suspected prostate cancer; male breast cancer; pregnancy; lactation; hypersensitivity to methyltestosterone; severe hepatic impairment.
Known hypersensitivity to testosterone or any component; history of or suspected prostate cancer; breast cancer; active thrombophlebitis or thromboembolic disorders; severe hepatic or renal impairment; pregnancy or lactation.
Data Pending Review
Data Pending Review
Take with food containing fat (e.g., avocado, nuts, olive oil) to enhance absorption. Avoid grapefruit juice as it may increase testosterone levels via CYP3A4 inhibition. Limit alcohol due to potential liver effects.
No specific food interactions. Grapefruit and grapefruit juice have no known interaction with testosterone gel. Avoid alcohol-based products on application sites as they may affect absorption. No dietary restrictions.
Android 25 (methyltestosterone) is an androgen. First trimester: Virilization of female fetus, including clitoromegaly, labial fusion, urogenital sinus abnormalities if exposure occurs before 12 weeks gestation. Second and third trimesters: Continued risk of female pseudohermaphroditism, and potential for masculinization of female external genitalia. Androgens can cross the placenta and may also cause skeletal abnormalities and growth retardation. Pregnancy category X.
Testosterone is classified as Pregnancy Category X. Use is contraindicated during pregnancy due to the risk of virilization of the female fetus, including clitoromegaly, labial fusion, and urogenital sinus abnormalities. Risks apply across all trimesters.
Methyltestosterone is excreted into breast milk; M/P ratio not established. May cause virilization in female infants and premature sexual development in male infants. Androgens can suppress lactation. Use during breastfeeding is contraindicated.
Excretion into breast milk is unknown; however, testosterone may suppress lactation and cause virilization in the infant. The M/P ratio has not been determined. Breastfeeding is not recommended during therapy.
Android 25 is contraindicated in pregnancy, so no dosing adjustments are applicable. If used inadvertently, discontinue immediately. No pharmacokinetic data to guide dose changes; avoid use entirely.
Testosterone is contraindicated in pregnancy. No dosing adjustments are applicable; therapy should be discontinued immediately if pregnancy occurs.
Category C
Category C
Android 25 (testosterone undecanoate) requires absorption via lymphatic system; administer with fat-containing meal. Monitor serum testosterone levels 3-5 hours post-dose. Avoid in patients with breast cancer or known or suspected prostate cancer. Risk of polycythemia; check hematocrit before and during therapy.
Apply Testim gel to clean, dry, intact skin on shoulders and upper arms. Avoid application to genital area or abdomen. Allow gel to dry before dressing. Wash hands thoroughly after application. Monitor serum testosterone levels 14 days after initiation. Avoid skin-to-skin contact with others until gel is dry. Testim may transfer to others via skin contact, causing unwanted androgen exposure.
Take capsules with meals, especially those containing fat, to improve absorption.Do not chew or crush capsules; swallow whole.Report signs of deep vein thrombosis (leg swelling, pain) or pulmonary embolism (sudden dyspnea, chest pain).Women of reproductive potential should avoid pregnancy; use effective contraception.Keep out of reach of children; testosterone can cause serious harm if accidentally ingested.Regular blood tests (testosterone, hematocrit, PSA, lipid profile) are required.
Apply Testim exactly as prescribed, once daily in the morning.Do not apply to scrotum, penis, abdomen, or broken skin.Let the gel dry completely before dressing or bathing.Wash hands with soap and water after applying the gel.Avoid direct skin contact with others (especially women and children) until the gel is dry.Store at room temperature, away from heat and open flame.Report signs of excessive testosterone (e.g., acne, hair loss, mood changes) to your doctor.Testim is not for use in women or children.Do not use if you have prostate or breast cancer.Regular blood tests are needed to monitor testosterone levels and prostate health.