There is no research showing that one format or the other is more effective, BUT the only RK study done on humans thus far was on a proprietary combination formula.
As far as other ingredients go, it really depends on what they are. Read the label and look up names which are unfamiliar. Look for ingredients with scientific studies backing their benefits.
Since raspberry ketone itself can act as a stimulant, you should be cautious about supplements with added caffeine if you are sensitive to caffeine or have certain medical conditions.
Products vary, so you should follow the instructions on the label. However, 100mg of raspberry ketone per day is mentioned on the Dr. Oz site as an adequate dosage. Most products contain more. We recommend that you stay away from products with the highest amounts because of the possibility of adverse effects. Raspberry Ketone acts like a stimulant, so you could experience anxiety, upset stomach or an inability to sleep.
In our opinion, more than 500 mg per dosage is probably too much for most people!
As long as you need to. A study on people taking a raspberry ketone based product showed noticeable results at around 4-8 weeks.
None! While the Dr. Oz TV show often focuses upon exciting new discoveries and their benefits,they NEVER endorse a specific brand or product. This is a long-standing policy, and clearly stated on the show's web site.
If you run across a product which claims to be endorsed by the famous doctor, you can be certain that this is a false claim. That's a product you should probably avoid!
While considered safe for most people, RK may not be a good choice for you if you have high blood pressure, are pregnant or nursing, or have certain other medical conditions. Read more about the safety and side effects of this supplement.
When in doubt, it's always best to get an opinion from your physician!
Be careful of what you're buying! Read reviews and look for trusted brands.
Unfortunately, to save money, some diet supplements are manufactured overseas under questionable conditions. The most trustworthy products are those made in the USA in a GMP certified lab - this assures that the product was manufactured to strict standards.