When sniffed, dosages of pulverized seeds are 150 - 500 mg for mild to medium effects, but it will not be a strong psychedelic journey.

For strong psychedelic effects, 1 gram of the pulverized seeds is required for a Sniff.
The amount of a traditional sniff-mixture varies, depending on the amount of Yopo seeds contained in it. So it is possible that up to 2 grams are required with traditional sniff-mixtures.

Smoking the seeds is also possible. The dosage ranges from 5-8 seeds, depending on the desired strength. The cigarette or joint should only be smoked half way for first timers, to check the strength of the effects and seeds!