Each Restandol® Testocap (oral testosterone product) consists of 40mg Testosterone Undecanoate in oily solution. It is to be administered orally and therefore preferred by many due to convenience. Nonetheless, the amount of drug reaching the general circulation through the gastro-intestinal tract could be affected by many factors. Once absorbed, testosterone passes through the portal vein into the liver initially before enters the blood stream. Within the liver, testosterone undergoes what commonly known as ‘first pass metabolism’ by the liver enzymes. The proportion of ingested drugs that gains access to the systemic circulation intact thereafter is known as bioavailability. Bioavailability of testosterone by oral route is considerably lower than injection due to this first pass metabolism, which explains the reason behind the vast difference between the usual oral dosage form (e.g. 120-160mg/ day) and the injection form (e.g. 1000mg/3 months).
Restandol® is licensed to be prescribed for patient with androgen deficiency. It should be taken in its original form without chewing. Testosterone is oil soluble and therefore is to be taken after food to increase absorption. Half of the daily dose should be taken in the morning and the rest in the evening; if uneven number of capsules are required per day, larger number of capsules should be taken in the morning.