Learn Portuguese (Portugal): Este creme hidrata muito mais do que o outro. - This cream hydrates much more than the other.

The phrase mais do que simply means 'more than'. To intensify the comparison and say 'much more', we place muito directly before the comparative word mais. This is the standard way to intensify a comparative structure in Portuguese.

Could I say mais que instead of mais do que in this sentence?

Yes. When comparing two things, do que and que are generally interchangeable. Using do que is very common and sounds natural in European Portuguese, but muito mais que o outro would also be completely correct.

Why do we say o outro instead of just outro for 'the other'?

When 'other' acts as a pronoun replacing a specific noun (in this case, creme), you must include the definite article. Because creme is masculine, it becomes o outro (the other one). If we were comparing a feminine noun like loção (lotion), it would be a outra.

Can I put the intensifier at the end, like mais do que o outro muito?