Hello, thanks for asking question. Meftalspas will not affect your fertility in fact it is safe drug even during pregnancy and may benefit pregnant lady. There are some basic side effects of Meftal Spas Tablet which includes visibility problem, vomiting sensation, headache, intense sweating, unusual sleepiness, hungriness, itchiness etc. As these are very basic side effect which doesn t harm any part of our body and these problems disappears after 2-3 days of use but if the problem continues, you should immediately consult the doctor. Severe side effects includes pain in joints, soreness in muscle, intense constipation, unclear vision(blurred or hazy Vision), problem in urinating, tiredness and uneasiness, gloominess, figment of the imagination, problem in moving around, black stool, change in heart beat, memory problem, nasal blockage, dark colored vomiting. If the person is allergic then they should let the doctor know that she is allergic to the medicine because the person with allergic behavior will cause lot of allergy in different mode after consuming Meftal Spas Tablet. Hope it will help. Take Care!