My boyfriend smokes marijuana and cigarettes on a regular basis. what kind of impact will this have on his fertility?

Adverse: Yes, marijuana and cigarettes both have the potential for an adverse effect on sperm. There are a number of published papers and abstracts indicating problems with sperm motility, fertilization, and sperm quality in users.

Probably none but: Overall, there is no clear evidence that marijuana impairs fertility. Some research studies have found lower testosterone in heavy marijuana users ; that sperm in marijuana users may "poop out" but epidemiologic studies have found no evidence of impaired fertility in marijuana users. See http://www.Cannabismd.Net/fertility/ re: cigarettes, studies are mixed but effects seem minimal-see comment:.