testosterone transdermal gel (AndroGel, Foresta, Testim, Axiron)

Indications

• androgen replacement therapy for andropause
• gender-affirming hormone therapy

Dosage

• AndroGel 1% & 1.62%:
  • start 50 mg* QD (5 g Androgel)
    • 4 pumps of 1%; 2 pumps of 1.62%
  • apply to shoulders, upper arms, or abdomen
  • increase to 75 mg QD & then to 100 mg QD if needed
  • serum testosterone 2 weeks after starting Androgel
• Foresta 2%
  • start 40 mg (4 pump actuations) QD in AM
  • apply to thighs
  • max dose: 70 mg QD
• Testim 1%
  • start 50 mg* QD
  • apply to shoulders or upper arms
  • increase to 100 mg QD if needed
• Axiron 2%
  • start 60 mg (2 pump actuations) QD
  • one pump actuation applied to each underarm
  • increase to 90 mg QD & then to 120 mg QD if needed
  • reduce to 30 mg if needed

* mg of testosterone

Adverse effects

• use by older men with mobility problems may increase cardiovascular risk
• not associated with subclinical atherosclerosis*
• skin-to-skin transfer to women & children with virilization
• increased risk of
  • gynecomastia
  • polycythemia
  • venous thromboembolism (GRS9)
• see testosterone

* trial only assessed atherosclerosis progression, not cardiovascular events

• drug adverse effects of androgens

Laboratory

• large within-individual variations in serum testosterone levels, thus 2-hour post-application serum testosterone is a poor indicator of serum testosterone on another day

Notes

• application to underarms & to thighs is an attempt to reduce skin-to-skin transfer to women & children

More general terms

• testosterone topical; testosterone transdermal