I wrote this in response to a question on meso where a few people were talking about supplements they were buying from amazon. Not directly related to this question, but I did the research and there are not really many good places online that I found that compile this sort of information, and it might save some people from being ripped off.
After buying 3 different brands of P.E.A. palmitoylethanolamide on amazon US and in all 3 the pills weighed less than the advertised contents ( one weighed 300mg , was meant to have 1400mg of stuff in it ) I did a fair bit of research on what supplements actually had what they advertised inside. Most are just selling you half or so of what they claim to bulk up their profits, some none at all, but some , especially products directed at "mens' issues" are contaminated with PDE5 inhibitors deliberately. No problem with the drug but taking a random amount of any drug unintentionally is a bad idea.
As far as I can tell at least half of all the supplements sold on Amazon US are dodgy, a lot tell you the pill size and you can work out that what they say is in them will not fit in a pill that size. There is no way this is anything other than deliberate intentional fraud. There are few regulations on supplements in the US, Amazon claims their sellers have to provide proof of their contents but there is no evidence of this actually happening, and almost none of the sellers have websites with genuine test results let alone independent third party testing.
iherb is probably a better source, they do not sell most of the brands I am sure are dodgy or think are probably dodgy. Their california gold brand does have test results but despite their claims they are not independently tested, but they get a lot of points for even bothering with the issue and showing any kind of test results.
NOW is a reasonably priced brand that publishes a lot of tests on their products and a lot of other brands, and most fail to have anywhere near the advertised contents. Obviously they have no motive to publish bad results on their own products but the fact that they bother to test anything to me suggests it actually matters to them and they dislike having to compete with companies defrauding their customers.
The biggest giveaway is if the well known brand charges 3 or 5 x the amount that the cheap brand does, then the cheap one is probably dodgy. I have looked up the cost of buying the ingredients in small bulk quantities from china and often they are selling the supplements for less than the cost of the ingredients, definitely applies to urolithin a, astaxanthin and anything fashionable or new.
A good percentage of the expensive ones are fine , the absolute cheapest ones are usually dodgy, finding reasonably priced ones that are probably good is the best you can get usually. Getting a batch COA is never going to happen.
Brands that are ok, and not super expensive as in all or most tests are fine or at least reasonably close are NOW, vitacost, henry blooms, nutricost, neurogan, bulk supplements, best naturals, horbaach, vitamatic, source naturals, swanson, solgar, nutragold,
sonora, kirkland, nootrpic depot, natrol, Jarrow Formulas, Thorne, Pure Encapsulations
This is not meant to be an exhaustive list, and a few of them had results of 70% or so in one test, but were mostly ok.
Trying to list all the bad brands is nearly impossible, if they are new and from the US and don't have a website then it is very likely they are dodgy. If the company has been around for years they are much less likely to be ripping you off. If it has a pile of different compounds or herbs mixed in , say more than 3 or 4 then almost all are massively underdosed at best. If they advertise capsule contents over a gram with more than one component most are dodgy with exceptions for fish oil etc.
