# Saliva as spermicide? **URL:** \ **Category:** Factual Questions\ **Created:** [November 19, 2007, 12:40am UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975 "2007-11-19T00:40:21Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![appleciders](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@appleciders](https://boards.straightdope.com/u/appleciders)\ **Post date:** [November 19, 2007, 12:40am UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/1 "2007-11-19T00:40:21Z")
Now I don’t think I believe it myself, because I heard it third-hand, through a friend I’d trust from a friend of hers that I distinctly distrust. But that was the claim made last night- that sperm could not be viably transmitted via saliva, and that a pregnancy couldn’t result from sperm being passed from one mouth to another and then into the vagina. I suppose I could see where the pH of saliva or something like that would be inhospitable, but actually impossible, to the point where it would actually be safe? Can anyone shed light on this for me? ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [November 19, 2007, 3:45pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/2 "2007-11-19T15:45:49Z")
This sounds like one of those stupid highschool rumors about pregnancy prevention. There is also the one where you can’t get pregnant if you have sex standing up. Sorry, I was unable to come up with anything definitive, but I think there will probably be somebody who knows better to come along soon. ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [November 19, 2007, 3:52pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/3 "2007-11-19T15:52:25Z")
Googling “saliva spermicide” turns up [this](http://answers.yahoo.com/question/index?qid=20071007095350AAWC3Ep) discussion. Apparently the teensy-weensy, itty-bitty grain of truth in your friend’s factoid is that if you’re trying to get pregnant, you want to avoid anything in the vaginal area that might possibly inhibit the sperm’s ability to swim upstream, and human saliva, like many other substances (baby oil, K-Y Jelly) does have a slight effect on sperm, and thus if you’re having sex in order to get pregnant, you want to avoid the use of saliva as a lubricant. But as for saliva being an outright, automatic, Quik-N-EZ spermicide, in the sense of “instantly killing them on contact”, no, apparently not. The normal pH of saliva is [“between 6.0 and 7.4”](http://www.enotes.com/science-fact-finder/human-body/what-normal-ph-blood-urine-saliva) According to the [Wiki article](http://en.wikipedia.org/wiki/Spermicide) on spermicides, both lemon juice and lactic acid have been shown to have varying degrees of effect on sperm in the laboratory. The pH of lemon juice is 2.3. The pH of buttermilk, which contains lactic acid, is [4.41 - 4.83.](http://www.cfsan.fda.gov/~comm/lacf-phs.html) When you’ve got saliva that’s as acid as lemon juice, you still won’t have an effective spermicide. I would hazard a guess that transferring a mouthful of semen to a fertile woman’s vaginal area would have a good chance of resulting in a baby nine months later, not least because any spermicidal effect of the saliva is only going to be on the sperm on the outside of the big blob of semen, but the ones on the inside–all remaining 1 billion of them–will be perfectly free to wend their merry way up the vagina. ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [November 19, 2007, 3:54pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/4 "2007-11-19T15:54:53Z")
My mistake. I googled “saliva birth control” and got a bunch of birth control tests. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [November 19, 2007, 4:57pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/5 "2007-11-19T16:57:00Z")
Wait, so the claim is that if a woman gives a man a blowjob, kisses him and then he goes down on her, it’s highly unlikely she’ll get pregnant? I think that’s about right, is only because the number of sperm present after she swallows is pretty darn small. The number sticking to her tongue and transfered to his tongue with a kiss even smaller, and the tongue is not the best applicator of semen, unless it’s eight inches long (and if that’s the case, my email’s in my profile!) Or is the claim that if a woman gives a man a blowjob, spits the semen into his mouth and he spits it up her vagina that it’s highly unlikely she’ll get pregnant? I’m not so prepared to believe that. The pH of saliva varies with the time of day and what you’ve eaten recently, but it’s generally around 6.4. The best fertile conditions generally have a vaginal pH of between 7.0 and 8.5. While this is certainly higher than the saliva pH, it’s worth noting that Buffergel, an actual spermicide which works through having a low pH, has a pH of 4. In short, if you are TTC (trying to conceive) and having trouble, then you might want to try to use a semen friendly lubricant like Pre-Seed instead of spit. But if you’re trying not to get pregnant, I wouldn’t rely on spit to do the job. [http://biomedx.com/pH/page3.html](http://biomedx.com/pH/page3.html) [http://www.storknet.com/cubbies/infertility/lubricants.htm](http://www.storknet.com/cubbies/infertility/lubricants.htm) [http://www.sciencedirect.com/science?\_ob=ArticleURL&\_udi=B6T6K-42NRV8S-64&\_user=10&\_coverDate=08%2F22%2F1997&\_rdoc=1&\_fmt=&\_orig=search&\_sort=d&view=c&\_acct=C000050221&\_version=1&\_urlVersion=0&\_userid=10&md5=b796eadbb13e7bdcfe6462c41bb60b15](http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6K-42NRV8S-64&_user=10&_coverDate=08%2F22%2F1997&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b796eadbb13e7bdcfe6462c41bb60b15) ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [November 19, 2007, 5:31pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/6 "2007-11-19T17:31:01Z")
[QUOTE=WhyNot] . . . if a woman gives a man a blowjob, spits the semen into his mouth and he spits it up her vagina . . . [/quote] Next time gays are accused of having strange sexual practices, I’m gonna remember this. ---
**Author:** ![Santo\_Rugger](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger)\ **Post date:** [November 19, 2007, 5:37pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/7 "2007-11-19T17:37:35Z")
So, one semen says to the other, “Do you think we’re about to reach the egg?” “Not sure,” said the other, “but we’re passing the esophagus now!” ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [November 19, 2007, 5:41pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/8 "2007-11-19T17:41:19Z")
[QUOTE=panache45] Next time gays are accused of having strange sexual practices, I’m gonna remember this. [/QUOTE] Wait, wait! I’ve never done this, nor heard of it, I’m just trying to figure out how saliva as a spermicide is meant to be practical, and how far those who advocate it are willing to take their chances! (The part about spitting a man’s cum back into his mouth is a real thing, though. It’s called snowballing, I hear. I’ve never done that, either. And I guess it’s not exclusive to straight sex.) ---
**Author:** ![Darryl\_Lict](https://avatars.discourse-cdn.com/v4/letter/d/7cd45c/32.png) [@Darryl\_Lict](https://boards.straightdope.com/u/Darryl_Lict)\ **Post date:** [November 19, 2007, 7:49pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/9 "2007-11-19T19:49:35Z")
[QUOTE=WhyNot] (The part about spitting a man’s cum back into his mouth is a real thing, though. It’s called snowballing, I hear. I’ve never done that, either. And I guess it’s not exclusive to straight sex.) [/QUOTE] Wow, you learn something new every day! Ignorance fought! ---
**Author:** ![appleciders](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@appleciders](https://boards.straightdope.com/u/appleciders)\ **Post date:** [November 19, 2007, 7:49pm UTC](https://boards.straightdope.com/t/saliva-as-spermicide/426975/10 "2007-11-19T19:49:36Z")
[QUOTE=WhyNot] Wait, so the claim is that if a woman gives a man a blowjob, kisses him and then he goes down on her, it’s highly unlikely she’ll get pregnant? [/QUOTE] This is indeed the situation under discussion, and my analysis was the same as yours- it’s a lousy way to try to get pregnant, but not exactly a birth control method either. Thanks!