title: Interpersonal testosterone transfer after topical application of a newly developed testosterone gel preparation.
abstract: OBJECTIVE
  Transdermal testosterone gel treatment is an effective androgen substitution therapy with several advantages over conventional substitution therapies. Whereas side-effects due to overdosing of hypogonadal patients are unlikely, testosterone gel application without protection may cause severe side-effects in other subjects (partners, family members) by contamination. Therefore, the risk of testosterone transfer of a newly developed 2.5% testosterone gel preparation was evaluated.
  
  
  METHODS
  In two clinical randomized open single-centre studies on healthy male volunteers the percentage of testosterone remaining on the skin after gel application over time (n = 12) and the possibility of a transfer of testosterone to another person (n = 28) was evaluated. In the second study the endogenous testosterone production in the receiving subjects was suppressed by injecting 400 mg norethisterone enanthate (NETE).
  
  
  RESULTS
  After 8 h approximately 60% of testosterone applied to the skin could be recovered. When the skin had been previously washed with water, only about 14% of applied testosterone could be recovered. After intense skin contact with a volunteer who had applied testosterone before on his forearm, no increase in testosterone serum levels could be found in NETE-suppressed men.
  
  
  CONCLUSIONS
  Although considerable amounts of testosterone remain on the intact skin for several hours after evaporation of the alcohol vehicle, contamination of a second, especially female or prepubertal, subject causing side-effects seems very unlikely.
authors.affiliation: Institute of Reproductive Medicine of the University, Domagkstrasse 11, D-48129 Münster, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Rolf
authors.forename: U
authors.initials: U
authors.lastname: Knie
authors.forename: G
authors.initials: G
authors.lastname: Lemmnitz
authors.forename: E
authors.initials: E
authors.lastname: Nieschlag
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000704:Analysis of Variance; D005782:Gels; D006727:Hormone Antagonists / Q000494:pharmacology; D006801:Humans; D007006:Hypogonadism / Q000188:drug therapy; D008297:Male; D009640:Norethindrone / Q000494:pharmacology; D012306:Risk; D012869:Skin Absorption; D013739:Testosterone / Q000008:administration & dosage* / Q000009:adverse effects* / Q000097:blood / Q000493:pharmacokinetics; D013997:Time Factors
chemical_list: D005782:Gels; D006727:Hormone Antagonists; D013739:Testosterone; D009640:Norethindrone