Do whitening toothpaste, mouthwashes, and strips contain bleaching agents?

[sai]

I was shocked to find most teeth-whitening “solutions” on the market contain bleaching agents packed with harmful chemicals and toxins that do more harm to health.

 

[MattKW]

I have yet to see scientific evidence supporting Janina products. There's nothing to back up their claims on their website. Unless you want to email them and ask for links to scientific literature...
4 mins is unnecessary and excessive. Major brands like Colgate, Macleans, Sensodyne are very careful to avoid overly abrasive particles, but I wouldn't trust anything less reputable that just appears on the internet.