Levonorgestrel CAS:797-63-7

Oral contraceptives, levonorgestrel, also known as D- norethindrone, left Kanok ketone, is currently the most widely used oral contraceptives, the racemic optically active part of norethindrone, the activity ratio norethindrone strong double dose can be reduced by half, adverse reactions are also reduced accordingly. Rapid oral absorption, 0.5 ~ 1h, reached the peak. t1 / 2 van 10 ~ 24h.Protein binding rate of 93% tot 95%, bioavailability, mainly located in the liver, kidney, ovarian and uterine body's organs and tissues, and its metabolites, mainly in the form of glucuronide and sulfate salts from the urine and feces in vitro. And ethinyl estradiol combination as a short-acting oral contraceptives. Its dual photo and three photo adverse reactions less, closer to women's normal hormone secretion type. Women can be used for emergency contraception, namely failure (condom slippage or breakage, coitus out of control, rhythm miscalculation, etc.) in the same room of post-coital contraception measures unprotected intercourse or other contraceptive methods.

1. Oral contraception:
At low doses, levonorgestrel is used in monophasic and triphasic formulations of combined oral contraceptive pills, Levonorgestrel is used for promoting the synthesis of protein and reduce the decomposition of amino acid, and for improving muscle hyperplasia, action and enhance male sexual characteristics.

2. Emergency contraception:
Levonorgestrel is used in emergency contraceptive pills (ECPs), both in a combined Yuzpe regimen which includes estrogen, and as a levonorgestrel-only method. The levonorgestrel-only method uses levonorgestrel 1.5 mg (as a single dose or as two 0.75 mg doses 12 hours apart) taken within 3 days of unprotected sex, with one study indicating that beginning as late as 120 hours (5 days) after intercourse could be effective.

3. Intrauterine system:
Levonorgestrel is the active ingredient in the Mirena & Skyla (Jaydess) intrauterine system.The levonorgestrel-only method uses levonorgestrel 1.5mg (as a single dose or as two 0.75mg doses 12 hours apart) taken within 3 days of unprotected sex, with one study indicating that beginning as late as 120 hours (5 days) after intercourse could be effective.

4. Contraceptive implants
Levonorgestrel is the active ingredient in Norplant and Jadelle.

5. Hormone replacement therapy
Levenorgestrel is combined with 17-beta estradiol in the Climara Pro hormonal patch.