im using gosmile, and have started as of tonight.... im meant to have significantly brighter teeth in 10 days i think.... i will let u know how i go... apparently it is the strongest whitening that you can do at home... it was $105 delivered to my door and you have these little individual viles to use each time that you rub in circular motion on your teeth for two minutes in total.... hopefully it will work.... i couldn't handle the trays in my mouth so went with this option.