Both!

From my understanding, as a natural lubricant it is totally sperm friendly, & a lot cheaper than products such as pre-seed.

It also affects the ph balance of the cervial mucus, which can help some couples......I remember reading that in the US & UK they do "post-coital" tests which measures the ph balance of the semen and cervial mucus combned, and some womens CM simply kills of sperm straight away, wheras the egg white can neutralise this impact.

(Post-coital testing is not routinely done is Australia, but I sometimes wonder if maybe it should......it would maybe solve some peopels "unexplained fertility"? I imagine it is fairly undignified, but I'd have been happy to undertake the test to get some answers!)

HTH........