Let's talk about what makes a quality resveratrol supplier.

Are they registered with the FDA?  

While it is not necessary to register with the FDA it helps indicate a company is serious about its products.

Is there a phone number you can call?  

A company should have contact information prominently displayed.  If they do not, are they hiding something?

Try contacting the company via email and see how long it takes to get a response. Quality customer service is important.

Does the company clearly list the ingredients in their resveratrol product and are the amounts listed as well?  

You should be able to easily identify where the resveratrol comes from, for example: Japanese Knotweed or Grape Seed Extract.

Can the company provide an independent laboratory test confirming the purity and quality of their resvertrol product?

Resveratrol is often manufactured overseas and it is important for companies to monitor the quality of the product.  Ask to see a verification if it is not posted on their website.

Resveratrol costs money to make and most companies will not offer it for free. Those who do are usually selling inferior products and looking to make a quick buck off of you by adding high recurring charges after your trial period elapses.

Use your common sense when buying supplements online.  If it sounds to good to be true then it probably is.