<p>During continuous treatment regimens with Lynestrenol, breakthrough bleeding or spotting will occur frequently (over 10 per cent) during the first two months. Later on the frequency gradually decreases. During cyclic treatment regimens breakthrough bleeding and spotting will be seen occasionally (1-10 per cent). Temporarily increasing the dose will control the bleeding in most cases. Other adverse events which occur frequently (over 10 per cent) are : change in libido (both increase and decrease), nausea or other gastrointestinal disturbances, and weight increase. Adverse events which may be observed occasionally (1-10 per cent) or rare (less than 1 per cent) are : headache or migraine, dizziness, nervousness, depression, increased sweating, acne, hirsutism, chloasma, rash, pruritus, jaundice, change in lipoprotein profile, alterations in liver function tests, amenorrhoea, menstrual irregularity, reduced glucose tolerance, breast pain, oedema. Most of these adverse events are transient and of minor importance in many cases.</p>