Yes, the effects can differ because you have two completely different materials being utilized. Plain leaf can be gentler or depending how many leaves you have but extracts are potent by themselves, even 5x-10x. Use a scale and adjust your dosage. Seeds are not common, no. I think there was a Nexian on here a while ago who figured out a way to acquire seeds, might have to dig that out in search, though.

I wish you well on your entheogenic salvia journeys! :thumb_up: