Were you led to believe there would be serotonin? Do you have to get yours store bought? (Which is totally fine BTW.) Then this is the sticker for you!
Measuring in at 2.5 inches tall, it is weatherproof, waterproof, and UV protected so you can put it on your emotional support water bottle and run it through your dishwasher or put it on your car and run it through your local car wash if that’s your thing.