I did a double session for weight loss and smoking and found it to be a bit too long. So I did not return for follow up sessions. On the upside I have been smoke free for 14 weeks now (I have put on 6kg). I had tried everything so this was my last resort. Thank goodness the quit smoking worked. I suffered from terrible headaches for about 3 weeks other than that I had no other side effects. I wasn't grumpy or unbearable to be around unlike other methods I had used in the past. Thank you for an awesome gift (my health).