It's a sedative because it acts like valium.Have you ever smelled valerian? LOL LOL. Not sure I would want to use that in my soap.
I think its a sedative because the smell will knock you out.
Anyway, my precaution would be to always look into contraindications for any additive for soap.
Even though it a wash-off product and not a lot of stuff gets soaked through the skin, there are still some thngs contraindicated for certain age groups (children/infants), certain conditions (pregnancy, allergies), certain activities (being in the sunlight), and some additive ingredients can potentiate certain drugs and the customer would therefore be looking on the label to decide it it is safe for them to use.
I am NOT saying that Valerian root in soap would potentiate Valium taken orally, but they are contraindicated for simultaneous use, so even if I were to put it in soap (maybe via the HP method after the gel phase) I still would feel compelled to caution that it should not be used by persons taking sedatives, including alcohol. Another good reason not to use it, as this puts the soap into the category that makes soap a drug, per US federal standards. And it would become a labeling nightmare, not to mention the whole licensing requirement.
So, @Pbonnibel86, that's something else to think about when you think about additives in soap. Does the soap become a cosmetic or a drug by virtue of this potential additive?