Infertility Support Group
In vitro fertilization is one of the most common and utilized ways of treating conception problems. This support group is dedicated to those beginning their journey with IVF and needing support. Join the community and share your experiences, advice, and story with people going through similar challenges starting a family.
"One should buy the plain kind with no letters after it. The only active ingredient is guaifenesin, and it contains 100 mg per teaspoon. It is very important to avoid the versions that contain decongestants as those may dry up cervical mucus. Also, there is some conflicting information about whether dextromethorphan, the DM in some cough medicine names, may be linked to birth defects such as neural tube defects and cleft palate."
http://www.fertilityplus.org/faq/cm.html
Here is the site: www.preseed.com
I think you can also find it in some stores.