Will taking one tablet of ecstasy show on a drug test weeks later?

It takes four days for MDMA to get out of your system. But a body cleansing kit might do the trick. =]

Also MDMA is not specifically tested for in the standard 5-panel drug tests, but it is chemically closely to amphetamines that recent MDMA users will test positive in both amphetamines (a common test) and methamphetamine(a somewhat newer and less common test).Also, many of street ecstasy are not pure MDMA and includes amphetamines (and may also contain DXM, caffeine, ephedrine etc) which may trigger drug tests. Home test your self and look for good detox