You can absolutely detox from weed, because cannabis withdrawal has both physical and psychological symptoms, especially after heavy or long term use. Common withdrawal symptoms include irritability, anxiety, sleep problems, vivid dreams, decreased appetite, headaches, sweating, nausea, and stomach pain, which usually start within 24 to 72 hours after you stop and can last up to a couple of weeks in heavy users. On top of that physical detox process, there is a big psychological piece too, like cravings, mood swings, feeling low, and needing to break the habit of using to relax or sleep, which can linger longer than the body symptoms.