Optima is an elegant and sophisticated typeface, and that's something so universally agreed upon that it virtually became the Helvetica of cosmetics. Optima has been the go-to typeface for the cosmetics industry for decades; so much so that major brands that used it have recently been moving away from it.

It's not a bad choice but it's not something that's going to differentiate your product in the marketplace.

Anything but Optima, which represents the status quo, which is presumably non-organic.
Body Shop uses a plain old sans.

Ideal Sans. Example from the website of HFJ.

Sensibility.

I think Nick's advice is very important here. A similar font to Optima could be as well Angie Sans by Porchez (who designed the typeface for Le Monde and the Sabon Next revival), but then after all it is maybe too similar again. Just keep that in mind what Nick said.

What Nick said.
I would dare even more:
http://new.myfonts.com/fonts/liebe-fonts/liebe-erika/

Thank you for all your comments and suggestions. Choosing the write type seems a delicate balancing act as some of your chooses(in my opinion)lean towards elegance and others towards organic/friendliness.

Any suggestions on what weight I should use: regular/bold/thin? It has to be legible on product packaging.

Whatever looks good - you're the designer, have the courage of your convictions.