About the only thing that is any good in Flexitrinol is the glucosamine HCL content at 500mg, and even that is on the lower side of the effective dose range, some of the ingredients such as MSM need to be dosed at more than 100x the amount in the joint health supplement to have any effect on joint pain or mobility. This is pretty much standard across the whole supplement in terms of it’s underdosing.
If this had been a budget supplement we could’ve possibly been a little more forgiving, but at $40 a bottle (it used to be $80) it’s coming within the price range of the best joint supplements on the market, which tend to come in around $55-65 and contain between two times and four times (in the case of the number one rated FlexAgain) the active ingredients. Meaning that there isn’t really much that we can say in favor of them, meaning we’re going to be writing a somewhat negative flexitrinol review.
The good news for the product is that despite containing glucosamine HCL there aren’t a lot of reports of flexitrinol side effects despite it's inclusion of primrose oil that can actually make joint inflammation worse...
Even with that aside customer reviews aren’t exactly glowing, and genuinely don’t lend themselves to a recommendation, and our testers experience wasn’t great either.
All in all, we don’t recommend Flexitrinol.
a huge number of flexitrinol reviews, but we’ve got an even split of 5 and 1
stars, and seeing as there’s so little, we can usually make the assumption that
at least a couple of positive ones are people who work for the company.
All in all we have to give Flexitrinol a low score in terms of customer ratings. Then there is the fact that the negative reviews stating flexitrinol doesn't work line up with what we'd expect based on the lack of functional ingredient doses.
Glucosamine HCL 500mg – There’s nothing wrong with adding glucosamine into a joint supplement, it’s well backed and recommended by clinicians in many countries for joint pain and osteoarthritis.  The problem is that we’d generally prefer to see a higher dose although 500mg is the bottom end of potentially effective ranges.  This is a decent inclusion for flexitrinol, but this is as far as the good in the joint health supplement goes.
Jointflex 200m g – This is a mix of chondroitin sulphate and MSM, the ingredients themselves are ok and have both been shown to be useful in treating joint pain and improving joint mobility, but unfortunately they’re dosed so low that they can’t possibly do anything. MSM requires 3 grams and up to be effective for joint pain , and chondroitin doesn’t actually do anything by itself, simply adds to the efficacy of glucosamine  and even then it needs to be dosed at 250mg and it is only half of this 200mg blend. In short this is something of a failure of design by flexitrinol joint health.
Omega 3, 6, 9 90mg – This omega blend is where we really start to dislike Felxitrinol’s marketing. It's made up of a mix of flaxseed oil, primrose oil and fish oil.
When it comes to omega there’s a fair bit to explain here. We’ll start by saying for Omega 3 to be effective as a treatment for joint pain it needs to over 1000mg and it only makes up 75mg of this blend. So we’re not off to a good start.
Now, Flexitrinol themselves try to explain this away by talking about the types of omega oils, but there marketing is misleading.
DHA, EPA, ALA are the most important omega 3 oils (there are more, but they serve niche functions).  In terms of joint health DHA and EPA are all that matters . ALA is the precursor to the other omega oils and our body breaks it down to turn it into the other two, generally this is the plant version and why plant based omega oils aren’t very good as the body wastes most of ALA to make the other oils  (algae is fine, that’s mostly DHA and EPA).
As for the omega 6 and 9, these will largely come from the primrose oil, and make up 10mg and 5mg of the blend spefically, the problem is that they're pro inflammatory, meaning they will make inflammation worse.  This is the last thing that anyone with joint pain would want as it is only going to make the issue worse.
So, in short the magic proprietary blend is nonsense, and you’d be much better off taking a 1000mg omega 3 algae or fish oil supplement instead.
Boron 1mg – Lastly we have boron, this can be an effective anti inflammatory, but you guessed it, it needs to be dosed higher, 10x higher to be exact, so once again we’ve been let down by flexitrinol.
Considering that the marketing is misleading, the ingredients are underdosed, they miss out well backed ingredients that can fit into a single capsule (assuming that’s what there intention was, a one capsule supplement) like Boswellia, resveratrol and bromelain, we’re really not sure what the plan with this supplement was.
1 - https://www.nhs.uk/conditions/osteoarthritis/treatment/
2 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2686334/
3 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372953/
4 - https://www.nccih.nih.gov/health/glucosamine-and-chondroitin-for-osteoarthritis
5 - https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/
6 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9413343/
7 - https://www.ncbi.nlm.nih.gov/books/NBK564301/
8 - https://www.mountsinai.org/health-library/supplement/omega-6-fatty-acids