I've been taking ashwagandha for years. Tried many different products and learned a lot about various forms in the process. I wanted to share some info to help clear up questions regarding brand and dosages.
For doses, in general, it's the amount of "withanolides" (the active ingredient) rather than the total amount of ashwagandha in terms of mg's. It's similar in this sense to alcohol. 2 shots of Vodka is more alcohol than one beer (even though the beer has more volume. So look at the % of withanolides and multiply by the number of mg's to get an idea.
But then it gets a bit more complex. There are different qualities of withanolides (are they from the root, which is better), or are they from the root and leaves (which contains withaferin A, a cytotoxic chemical). Was the withanolide content measured by HPLC? This is the proper way to measure.
The quality of ashwagandha varies a lot. And different species seem to have different effects. It's not simply the amount of withanolides. It's always best to look at the scientific research when determining which kind to get.
The 2 most impressive forms of ashwagandha are new and exciting. There is KSM-66 and Sensoril. These are both pure ashwagandha extracts and both have their own advantages. KSM-66 has a great study showing how it can reduce anxiety. This is a good overview of KSM-66
. It is also certified organic, non-GMO, and has 5% withanolides.
Sensoril has 8% withanolides. It is an extract of the root and the leaves. It has it's own list of studies as well. Anecdotal reports I've heard say that KSM-66 is more calming in general, and Sensoril is more energy boosting. Here is some info about Sensoril
. That second link is from their own site, but you can click around and see the facts and clinical evidence.
Interested to hear if anyone here has tried either form and what your experiences have been.