Mast cells. Mast cells and basophils are generally thought to be the major sources of histamine and can themselves be modulated by histamine as they express H 1, H 2 and H 4 receptors, although how this varies between different mast-cell types is not yet clear.
3. The pill is to be taken soon after unprotected sex. It should be taken preferably within 24 hours and before 72 hours or else the pill may turn useless. 4. I-pill checks pregnancy by preventing ovulation or fertilisation or implantation of the fertilised egg. 5. I-pill is 95 per cent effective if taken in time.
Yes; or abstain from sex until one pill has been taken every day in a row for 7 days. Consider using emergency contraception if you have had unprotected sex in the previous 7 days and have missed 2 or more pills in the first week of your pack. Consider consulting with health care provider for more advice.