How long does the Sutro test cartridge last?

The Sutro cartridge has 90 tests available, and since it tests 3 times per day - it will last for roughly one month!

Can I use old cartridges?

We recommend not using cartridges older than 3 months, expired cartridges will provide inaccurate readings! If you don't have a good cartridge handy, send us an email and we will get you hooked up with one! 

Regarding the expiration of the cartridges, please look at the bottom side of the box it came in and there will be a date printed. This is the date your cartridge was filled and packed!

Date Format: mm/dd/yyyy

Can I exchange or return old cartridges?

Unfortunately, we do not exchange cartridges and we cannot use them if they're expired. If you end up with expired cartridges, please toss them and reach out to our Support team! As long as your paying for the monthly subscription, we can have a new cartridge shipped ASAP.