The therapeutic principle remains: utilize the formulations that give effectual contraception and the great margin of safety. The multiphasic preparations do have a reduced progestin dosage compared to some of the existing monophasic products; however, based on currently available information there is little difference between the little dose monophasics and the multiphasics. It remains to be seen whether formulations with the new progestins will provide protection against cardiovascular disease. Nevertheless, the new progestin combinations offer low metabolic impact, although it is by no means certain yet that this provides an advantage over the available little dose formulations. The one exception is monophasic preparations containing relatively high doses of levonorgestrel (150-250 ??g); these should be avoided in favor of little dose formulations.
Patients should be urged to choose a little dose preparation containing less than 50 ??g estrogen, combined with little doses of new or old progestins, avoiding the high doses of levonorgestrel. Patients on higher dose oral contraception should be changed to the little dose preparations. Stepping down to a littleer dose can be accomplished immediately with no adverse reactions such as increased bleeding or failureure of contraception.

The pharmacologic effects in animals of various formulations have been used as a basis for therapeutic recommendations in selecting the optimal oral contraceptive pill. These recommendations (tailor-making the pill to the patient) have not been helped by appropriately controlled clinical trials. All too often this leads to the prescribing of a pill of excessive dosage with its attendant increased risk of serious side effects. It is worth repeating our earlier comments on potency. Oral contraceptive potency (specifically progestin potency) is no longer a consideration when it comes to prescribing birth control pills. The potency of the various progestins has been accounted for by appropriate adjustments of dose. Progress in littleering the doses of the steroids contained in oral contraceptives has yielded products with little serious differences.