To kill yourself it won't do jack shit. If your plan is hurting yourself just make yourself nauseous and miserable for a few days I would say that would probably work. It'd be hypocritical of me to say don't OD as a form of self harm as I do it all the time, but if you do be aware of the risk you're taking. You may cause permanent damage to yourself and while the odds are low, they are never 0 that you could die unintentionally. I wouldn't recommend it, but I know that won't stop a self harmer.