It's drying (which is the point) but aside from that there isn't anything to worry about. A lot of people find that it helps clear up their acne as an added bonus. Also the name is actually Milk of Magnesia, and it's pretty cheap so you don't have much to lose by trying it out. Just be aware that it leaves a white cast on your skin that you have to wipe off in some way.

Hey! Thanks for the reply! I don't mind of its drying, but thanks for the reply. Do you know where I could buy it in England, and also how to persuade my family it's safe to use? I really want to not have to worry about my skin whilst in china on a school trip!

Also, would you moisturise before or after? And would the moisturiser get rid of the white of you do moisturise after?

In the US it can be found in a typical drug store or grocery store. If you can't find it in a local store, you can buy it online from a site like Amazon. Just make sure to get the original kind and not a flavored variety. The chance of your skin having a negative reaction is slim, and even if it did, you could just stop using the MoM. It's not like you're taking a big risk. I would apply moisturizer first and MoM second, and no, most likely the moisturizer wouldn't hide the white cast.

Thanks for helping me out. Unfortunately I noticed a very very minor difference whilst using MoM, I just went oilier a little later (about half an hour). It's all worth a try though, we won't succeed if we don't try eh?

I tried it and wasn't overly impressed. But hey, it's cheap so you might as well give it a whirl.