What would you go for?
I know a friend that needs some advice and I'm not too good with HQ information etc.
Apparently they both work wonders for her but she is more concerned of long term side effects.

I've never used Extra Claire so I can't speak on that. But as far as Bio Claire: we have a love-hate relationship. It always lightens me quickly but then sometimes the lighter skin comes with blemishes. And believe me, I know what I'm talking about because I have been using BC off and on for two years. Mostly on my face, chest and arms.

This time around, literally a week ago, I overused Bio Claire and it burned the holy hell out of my face. I credit this EXTREME mishap to my over-zealous application and less to the actual product. I felt my skin tingling like it was burning, which normally doesn't happen, and still applied BC anyway. Dumb, Dumb & Dumb! My skin was burnt, scaly and painfully red for almost 4 days and then it began to peel. I still have two pink spots but now, overall, my skin has returned to normal. It is really soft (after being damn near raw) and the peeling, haphazardly took away the dark spots I had.

After not using it nor any kind of chemical on my face, and once making sure my skin was completely healed I used bio claire again today. And it literally lightened my face in one day. The advice I can offer with bio claire is this: it will lighten quickly, but be cautious with it. Pay attention to your body and don't be a dummy and overuse like me. The only two downsides are: once you begin seriously using it, you will not be able to stop & possible acne. In my opinion the skin gets accustomed to it, and once you stop, you skin will look dull and will in the matter of a week or two, redarken. Unless you begin to use some other lightening product. I plan to stop using BC once I can purchase pure hydroquinone and after achieving my goal with that, I will continue with more natural skin lighteners.

Hope this helps.