The age treatment starts will depend on a number of factors which the endocrinologist has to take into account. In younger patients there is a balance to be made between the time treatment starts and the dosage used.

Before the age of 16 some doctors are reluctant to give the full adult dose of testosterone (around 200 – 400 mg per month) until it is sure that normal adult height is obtained. If full dose treatment starts too early it can risk fusing the growth plates of the long bones too early and full height is not obtained.

Once full adult dose treatment starts changes should normally start occurring within 6 months. One important point to bear in mind is that the levels of testosterone should be monitored during treatment so that the levels are of adequate adult dose throughout the treatment cycle.

For the younger patients, for ages from 13 – 16, doctors often use a step by step approach starting in small doses of testosterone, such as 50 or 100 mg per month. This is normally reviewed at 3 month or 6 month stages to see if there are any signs of pubertal development. If there is any increase in testicular size it could suggest that it is a case of delay of puberty rather than Kallmann syndrome.

The doctor will then re-check the levels of the pituitary hormones LH and FSH to confirm the diagnosis. If LH & FSH remain low the doctor may step up the dose up to adult levels, the rate this occurs will vary from patient to patient but in general by the age of 16 the full adult dose is normally given. The treatment is normally in the form of injectable testosterone (Sustanon or Nebido) as this gives the best effectiveness. Oral testosterone is unlikely to be suitable to patients with Kallmann syndrome.