A number of sources suggest 1 hour as the time for a dose of cactus alkaloids to take effect. SWIM wishes to caution you that this time may in fact be as much as 4 hours. Recently SWIM came into possession of 2100mg of cactus alkaloids. He took 400mg per hour for 5 hours, feeling absolutely nothing at all. He believed that the extraction technique had not been effective and the product had no potency. Then after the 5th hour he recognized he had entered a very strong entheogenic experience. It was good in many ways, but it was much stronger and longer than SWIM wanted. So SWIM cautions fellow voyagers... give cactus alkaloids plenty of time to make their presence known.