"Several studies report an improvement in depression after 3 weeks (68) or 1 month (38). Increase in good mood and a decrease in bad mood were noted after 3 weeks (68) or after 30 days (14). There was also an increase in motivation after 30 days which was maintained thereafter (14). Two studies using the Hamilton Depression Rating Scale found an improvement in depression after 6 weeks (75) or 8 weeks (76). A number of psychological variables (increase in sociability, decrease in anxiety, increase in concentration, and self-confidence) were apparent after 3 weeks (68). A decrease in fatigue and listlessness was found after 1 month (31) or 6 weeks (68). A transient increase in anger/hostility was found in eugonadal men whose testosterone levels were raised above normal after 2 weeks (77)."

"It is very likely that the positive effects of testosterone on depressive symptoms start as early as after 3–6 weeks, but will most likely take 18–30 weeks to find the patient with a significant improvement. A recent study in hypogonadal men receiving i.m. testosterone undecanoate demonstrated such effects. It is remarkable that effects were more pronounced in men with the lowest baseline testosterone levels"

"Effects on libido

Effects on libido, sexual desire, sexual thoughts and fantasies and satisfaction with sexual life manifest themselves rather rapidly: after 3 weeks (68) or 30 days (14). Some studies have measured these effects only after 3 months (31)."

"Effects on erection/ejaculation

Effects on erection also appear rather rapidly: after 3 weeks (68). Increase in morning erections occur after 3 weeks (68). An increase in percentage of full erections and sexual performance and satisfaction with erections was noticed after 30 days (14, 69), an increase of ejaculations and sexual activity after 2 weeks (70) and 3 weeks respectively (68). In patients with veno-occlusive dysfunction, testosterone undecanoate restored erectile function after a minimum of 3 months and a maximum of 11.5 months "

"The International Index of Erectile Function is a reliable, self-administered measure of erectile function that is cross-culturally valid and psychometrically sound, with the sensitivity and specificity for detecting treatment-related changes in patients with erectile dysfunction. It has five domains: erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction. Increases in the IIEF erectile function have been noted after 3 months

(35, 40) but increases in IIEF sexual desire, intercourse satisfaction, and overall satisfaction appear already after 6 weeks

(40). Maximal effects are usually achieved after 3–6 months

(72) but may take even up to 1 year in individual cases

(71). The data are summarized in

Fig. 4. "