Not everyone gets high using Delta-8 THC. But if it gets you high, how long does it take to properly set in? The onset time for Delta-8 varies from person to person especially depending on the method Delta-8 was administered. For instance, a value cartridge will kick in faster than an edible will. In most cases, Delta-8 THC cartridges kick in almost immediately. Then, the effect peaks a few minutes later and further sets in.