I've been getting my health supplements online and I find this website http://www.iherb.com/default rather reliable.
The delivery is pretty on time.
For instance, if I were to place my order SG time Monday morning, I'd be able to get it by Thursday evening if I select DHL as the preferred delivery method.
Sometimes iHerb will organise special promotion on the delivery charges or product discounts.
So it's worth while checking their website regulary to catch the best deals.
I also find the listing of the product expiry date very useful as it helps me decide how many bottles of the same health supplement to order for safe consumption.
Another plus point is the timely status updates available for your delivery tracking.
iHerb also sells skin care which I've not tried yet.
I'd like to check out the anti-aging products in my next health supplements replenishment order.
But do note on SG's custom regulation since GST is payable for purchase amount > $400 and also certain products are prohibited.
Note: I'm not being paid for this post. I'm just putting down my honest recommendation & feedback.