Table 1.

Advantages and disadvantages of available testosterone formulations

Route	Formulation	Advantages	Disadvantages
IM	T enanthate or cypionate	Relatively inexpensive, self-administered; predictable levels	Requires IM injection; peaks and valleys in serum T concentrations that may be associated with fluctuations in symptoms
	T undecanoate	Infrequent administration	Requires IM injection of a large volume (3 or 4 mL); coughing episodes after injection in some men
Transdermal	Gels (1%, 1.62%, or 2%)	Ease of application, good skin tolerability	Potential of transfer by skin contact; T concentrations may be variable from application to application; skin irritation in some men; moderately high DHT concentrations (of unknown significance)
	Patch	Ease of application, predictable levels	High rate of skin irritation at application site; reduced adherence with sweating
	T axillary solution	Good skin tolerability	Potential transfer to others by contact; T concentrations may be variable from application to application; skin irritation in a small proportion of patients; moderately high DHT concentrations (of unknown significance)
Transmucosal	Buccal tablets	Convenient	Gum irritation; dysgeusia; twice-daily dosing
	Nasal gel	Rapid absorption; avoidance of first-pass metabolism	Multiple daily dosing; cannot be used in men with nasal disorders
SC implant	Pellets	Infrequent administration	Requires surgical insertion; pellets may extrude spontaneously; risk of hematoma and infection
Oral	T undecanoate	Ease of administration	Requires twice-daily dosing; unfavorable effect on lipids and blood pressure

Adapted from (1).

Abbreviations: DHT, 5-dihydrotestosterone; IM, intramuscular; SC, subcutaneous; T, testosterone.