Salvia divinorum contains salvinorin A which will activate the opioid receptors in the brain. However, unlike most other psychedelics salvinorin A has an effect on the kappa(1) opioid receptor. The effect on this specific receptor can be experienced as hallucionogenic however also can be exprienced as not being pleasant in a lot of cases. This also explains why Salvia divinorum can’t be compared to other psychedelics: it simply doesn’t activate the same opioid receptors as for example Magic Mushrooms, Magic Truffles, LSD, etc.
About 10% of the users of Salvia divinorum claims to not feel (many) effects when having consumed Salvia divinorum. This is because of the fact that about ten percent of all people simply aren’t sensitive to salvinorin.
When Salvia divinorum is smoked the effects will usually be very heavy but will last for about 5 to 20 minutes. After these 20 minutes you can however have the feeling of the effects of Salvia divinorum for a couple of more hours till it totally fades. But when Salvia divinorum is taken through oral consumption the effects won’t be as strong but will last longer. In some cases hours, but most users claim it will be over its peak in about 1 to 2 hours.