Neem is not a cure-all product. It MAY be helpful for your sister's skin issues, but there are no guarantees as many people here will tell you. Is it wise to try to figure this out while she's pregnant? Especially since she's got concerns already?
Many people make their own soap as a way of managing their skin issues. Many have learned they do well using a gentle soap made with no fragrances or other additives. It's sometimes less about what you add to a soap, but what you DON'T add that's the important thing.
I'm not any expert on neem, but I've done some reading about it. From what I can tell, the active ingredients in neem are not chemically altered when neem is used in soap making. That's why neem soap is beneficial for some skin issues.
Even if some or all of those active ingredients are changed when neem is used in soap, however, you can't assume those secondary chemicals are non-toxic.
Many people make their own soap as a way of managing their skin issues. Many have learned they do well using a gentle soap made with no fragrances or other additives. It's sometimes less about what you add to a soap, but what you DON'T add that's the important thing.
...I wonder if whatever makes it "bad" is even left after soponification....
I'm not any expert on neem, but I've done some reading about it. From what I can tell, the active ingredients in neem are not chemically altered when neem is used in soap making. That's why neem soap is beneficial for some skin issues.
Even if some or all of those active ingredients are changed when neem is used in soap, however, you can't assume those secondary chemicals are non-toxic.