Table 2 Characteristics of testosterone replacement therapy (TRT) trials reporting both serum testosterone (T) and dihydrotestosterone (DHT) concentrations before and after treatment

Amory 2004 [32]

RCT

i.m.

100 mg TE/week

36 months

71 ± 4 (SD)

24

302 ± 48 (SD) ng/dL

hypogonadal

Arver 1997 [65]

open-label

i.m.

266 mg TE/26 days

3 weeks

58 ± 10 (SD)

27

121 ± 100 (SD) ng/dL

hypogonadal

Bhasin 2012 [66]

RCT

i.m.

125±mg TE/week

5 months

40 ± 7 (SD)

12

519 ng/dL (mean)

eugonadal

Borst 2014 [34]

RCT

i.m.

125 mg TE/week

12 months

69.2 ± 8.0 (SD)

31

264 ± 92 (SD) ng/dL

hypogonadal

Lakshman 2010 [67]

RCT

i.m.

125 mg TE/week

5 months

65.6 ± 4.3 (SD)

11

581 ± 168 (SD) ng/dL

eugonadal

Raynaud 2008 [68]

open-label

i.m.

250 mg TE/3 weeks

12 months

41.8 ± 12.4 (SD)

32

43 ng/dL (mean)

hypogonadal

Shubert 2003 [69]

open-label

i.m.

250 mg TE/3 weeks

12 months

31.9 ± 2.5 (SD)

14

63.6 ng/dL ±14 (SD)

hypogonadal

Wang 2010 [70]

open-label

i.m.

750 mg TU/4 to 10 weeks

21 months

>18

117

320 ng/dL ±111 (SD)

low normal T

Brockenbrough 2006 [48]

RCT

gel

10 mg T/day

6 months

58.9 ± 14.9 (SD)

19

218 ± 64 (SD) ng/dL

hypogonadal, renal disease

Cherrier 2003 [71]

RCT

gel

50-100 mg T/day

6 months

34 to 70

12

320 ± 90 (SD) ng/dL

low normal T

Chiang 2007 [72]

RCT

gel

50 mg T/day

3 months

20 to 75

17

213 ± 158 (SD) ng/dL

hypogonadal

Dean 2004 [73]

open-label

gel

50 mg T/day

9 months

58.5 (mean)

257

247 ng/dL (mean)

hypogonadal

Di Luigi 2012 [74]

open-label

gel

50 mg T/day

1.25 month

31.3 ± 7.5 (SD)

10

72 ng/dL (mean)

hypogonadal

Juang 2014 [75]

RCT

gel

100 mg T/day

3.5 months

24 to 51

14

302 ± 37 (SD) ng/dL

hypogonadal, osteoporosis

Kenny 2010 [53]

RCT

gel

50 mg T/day

12 months

79.9 ± 7.3 (SD)

69

380 ± 179 (SD) ng/dL

eugonadal, osteoporosis

Marin 1993 [54]

RCT

gel

125 mg T/day

9 months

56.7 ± 2.2 (SD)

10

455 ± 23 (SD) ng/dL

eugonadal, obese

Mazer 2005 [76]

RCT

gel

59 mg/day

2 weeks

52.4 ± 12.2 (SD)

28

226 ± 110 (SD) ng/dL

hypogonadal

Page 2011 [77]

RCT

gel

75 mg T/day

6 months

>50

27

204 ng/dL (mean)

hypogonadal, BPH

Swerdloff 2000 [78]

open-label

gel

100 mg T/day

3 months

51.3 (mean)

76

280 ng/dL (mean)

hypogonadal

Wang 2000 [79]

no placebo group

gel

100 mg T/day

2 weeks

26 to 59

10

179 ± 41 (SD) ng/dL

hypogonadal

Wang 2011 [80]

open-label

gel

60 mg T/day

4 months

51.5 ± 12.7 (SD)

135

215 ± 84 (SD) ng/dL

hypogonadal

Ahmed 1988 [81]

no placebo group

patch

15 mg T/day

6 to 8 weeks

34 to 54

5

45 ± 12 (SD) ng/dL

hypogonadal

Bals-Pratch 1988 [82]

not stated

patch

10 to 15 mg T/day

14 months

31 to 37

7

189 ng/dL (mean)

hypogonadal

Behre 1999 [83]

open-label

patch

2.4 to 3.6 mg T/day

7 years

35.9 ± 9.8 (SD)

11

147 ± 37 (SD) ng/dL

hypogonadal

Cunningham 1989 [84]

placebo-controlled

patch

15 mg T/day

8 weeks

33 to 66

12

43 ± 11 (SD) ng/dL

hypogonadal

Mazer 2005 [76]

open-label

patch

5 mg T/day

2 weeks

28 to 71

28

215 ± 110 (SD) ng/dL

hypogonadal

Meikle 1992 [85]

not stated

patch

12.6 mg T/day

single dose

24 to 66

6

161 ± 27 (SD) ng/dL

hypogonadal

Raynaud 2008 [68]

open-label

patch

2.5 mg T/day

12 months

40.7 ± 10.5 (SD)

131

43 ng/dL (mean)

hypogonadal

Franchimont 1978 [86]

oral

120 to 240 mg TU/day

9 weeks

16 to 51

10

120 ng/dL (mean)

hypogonadal

Roth 2011 [87]

open-label

oral

400 mg TU/day

1 day

18 to52

11

405 ± 14 (SD) ng/dL

eugonadal

Schubert 2003 [69]

open-label

oral

160 mg TU/day

12 months

34.5 ± 3.9 (SD)

13

63.6 ng/dL ±14 (SD)

hypogonadal

Van Coevorden 1986 [88]

RCT

oral

240 mg TU/day

12 weeks

40 ± 11 (SD)

19

161 ± 86 (SD) ng/dL

hypogonadal, renal insufficiency