In most people, the effects of SuperStrut 4-in-1 ED Tablets can last up to 36 hours. Even after the strongest effects of the medication have worn off, the medication is still in your system for up to a day after dosing - so do not take more than one dose daily. If you find your erection lasting 4+ hours, seek medical attention immediately as this is considered priapism and could have damaging effects on the tissues.