This website does not set-out to provide detailed information or advice on how to successfully make a suicidal gesture, as "gestures" can go wrong and end up in death, or medical complications. So people considering making a gesture may want to consider alternatives. See the section Help me for more information.
For anyone intent on a suicidal gesture, they may want to review the minimum lethal dose information (noting that calculating MLDs is notoriously unreliable), and take half or less of the MLD dosage, ideally of a drug that is rarely found to be lethal (e.g. ibuprofen). Note that many things, taken in the right quantity, can be lethal. Ensure the packaging of what has been taken is nearby, so on discovery the correct medical attention can be given. Consider having activated charcoal on hand for instant treatment (see Overdose treatment) and arrange to be discovered quickly.