return to Health Line main index

HEALTH LINE

Questions and Answers

Q
A 60 year old male patient with very low level of testosterone as shown in multiple blood tests over 2 years was prescribed injectable testosterone by his physician, an endocrinologist. I am looking for more info about this drug. The Rx was for 0.5 cc testosterone every 2 weeks, but does not mention how many milligrams this is. All our review of available literature has indicated that dosages are measured in milligrams relative to patient's weight. How should we interpret the Rx for 0.5 cc/2 wks in terms of milligrams? Thank you for any assistance you are able to provide.

A
There are two long-acting testosterone preparations, each with two concentrations, available-
Testosterone enanthate - 100 and 200 mg./ml. (cc.), and
testosterone cypionate - 50 and 200 mg./ml.

The prescribed dosage of 0.5 ml. could therefore contain 25, 50 or 100 mg.

Since the response to extrinsic testosterone is so variable, the amount given is rounded off based on general experience, and given for as long as it takes for plasma levels of testosterone to reach normal values and/or sexual response to occur. Long-term maintenance dosage is then determined - in practice to some conveniently measured volume of one or other of the preparations, eg. 0.5 or 1.0 ml.

The wide variation in individual responses is made obvious by the recommended dosage of 50-400 mg. every 2-4 weeks, intramuscularly. The treatment is continued for 2 or 3 years, or until adequate response occurs, then a lower maintenance dosage can be used. Others believe that the starting dosage should be about half the eventual maintenance dosage for 6 months to 1 year - then a common dosage is 200 mg. every 2 weeks.

Best wishes from Winnipeg.