Published 13th July 2023
Flexoplex promises you 12 known joint pain relief ingredients at about half the cost of what you'd pay for them individually. The catch, they're in about a tenth of the dosage you'd get if you paid the full price and thus are going to be entirely ineffective at relieving joint pain.
This is a common trick of less scrupulous joint supplements and unfortunately we see it here again today. Now, Flexoplex is not the worst joint pain supplement on the market by any stretch, and there are perhaps 3 to 4 ingredients here that are within their effective dose ranges (albeit at the low end), but this is of course not what they promise.
There is also the fact that competitors which charge about $10 a month more, do actually offer a full range of properly dosed ingredients (11 in the case of FlexAgain which we rated the number one joint supplements right now). In that case there are some joint supplements which do actually make good on these sort of promises.
Independent Flexoplex reviews are generally quite buried underneath their marketing, but those that we did find were as you'd expect from a supplement that overpromises a let down. Although the general consensus is that it does help, just it's not as good as was promised.
All in all Flexoplex won't be making our best joint supplements list any time soon, it's overpriced although could have some impact to improve joint pain due to the glucosamine  and boswellia extracts.  We should note however that there are $25 a month options which dose these ingredients more effectively, and as we've mentioned slightly more expensive options that do what Flexoplex claims to in offering a comprehensive joint supplement.
In short, we don't recommend Flexoplex, but it's not terrible.
Flexoplex reviews on amazon aren't bad overall, once you filter out the ones that were likely bought and paid for by the brand itself, obvious reviewing accounts etc, the general gist is that the product isn't terrible, just overpriced. Which is not too far off what we'd expect as there's definitely a couple of ingredients in here that should work for a lot of people.
Some bad flexoplex reviews generally suggested that it did nothing or caused nausea which isn't too uncommon for supplements in general, so we'd suggest that these concerns pretty much stack up with our expecations.
There were also a lot of positive reviews which stated that flexoplex did in fact reduce joint inflammation and improve joint mobility. As for the flexoplex reviews on other third party sites, TrustPilot was surprisingly positive, so much so that it does stack up as one of the best rated joint pain supplements that we've come across on the platform.
|- Good amount of some decent ingredients||- Most ingredients are under dosed|
|- Good customer reviews||- Overpriced for what it is|
|- 60 money back guarantee|| - Misleading marketing
Glucosamine sulfate 750mg - Glucosamine is a vital component of connective tissues and has been shown to improve flexibility, reduce joint pain, and protect against wear-and-tear. [1,3] It's actually prescribed as a supplement for arthritis in a lot of countries, and whilst the amount that flexoplex contains is on the lower side, it is still in the effective range for joint problems.
Chondroitin sulfate 600mg - Chondroitin plays a crucial role in protecting joints by lubricating them, absorbing impact, promoting cartilage production, and repairing damaged cartilage. In terms of studies on joint health, it's only been shown to support glucosamine and not to work as a standalone ingredient. 
While Flexoplex provides a decent amount of glucosamine and chondroitin, the proprietary blend and lack of transparency regarding ingredient dosages are major drawbacks and where things start to go wrong. On top of which glucosamine is in the low range of effective dosing and there is more chondroitin than needed in flexoplex.
Flexoplex Proprietary Blend 697mg - The proprietary blend in Flexoplex contains several ingredients, including MSM, cat's claw bark powder, rutin, boswellia serrata gum resin extract, Sodium hyaluronate (hyaluronic acid), bromelain complex, soy lecithin powder, trypsin complex, and boron aspartate. However, the exact amounts of these ingredients are not disclosed, which raises concerns about their effectiveness and potential filler content. Especially because there simply isn't enough space in the blend for almost any of the ingredients to be dosed effectively. With proprietary blends it is a legal requirement to list ingredients from largest to smallest.
MSM - Seeing as MSM has to be dosed at around 3-5 grams and is the largest ingredient in here, we're not off to a good start as the bulk of the blend is useless. As an ingredient it does seem to be good for joint health, the catch is simply tat there isn't nearly enough to alleviate pain in swollen joints. 
Cats Claw Bark Powder - We see this pop up in a lot of joint pain relief supplements, unfortunately it's not a great ingredient, there is very limited evidence that it can reduce pain and inflammation in humans, especially compared to more well proven ingredients such as curcumin or galangal extracts. 
Rutin - There's some evidence to suggest that rutin does improve joint function due to it being a powerful anti oxidant, which reduces oxidative stress in patients with osteoarthritis, the catch is that the effective dosage range starts at 400mg, and it's the 3rd ingredient on on 700mg list, meaning there would need to be 2 ingredients more heavily dosed and thus this is mathematically impossible. Realistically it's going to be at least 4 times too low to be effective at treating joint pain. 
Boswellia Serrata - Boswellia is actually a good ingredient for joint health supplements, and along with boron, it is the only ingredient in this blend that can mathematically (based on it's list position) be in a functional dosage, which is a minimum of 100mg. Boswellia has strong anti inflammatory properties and has been shown to relieve joint pain as well as over the counter pain relief in multiple trails. [2,8]
Bromelain - Bromelain is an enzyme taking from pineapple, it works by breaking down inflammatory cell surface adhesion proteins in the body, it's been shown to be quite effective and reducing joint swelling making it a good ingredient for any joint supplement, the catch, well at this point it's probably quite obvious, you need 100mg, and there can't possibly be 100mg in this blend. Soy lecithin powder - This needs to be in around 1200mg to be an effective treatment for joint pain. So once again we're having the same issue over and over again with Flexoplex. 
Trypsin - Trypsin is another enzyme which can work alongside bromelain to improve pain and inflammation, it's not a bad ingredient, but it's not a great one either. Theoretically it could be within it's effective range, although only just and it has only really be shown to work alongside effective dosages of bromelain and rutin as a support ingredient.  It has been shown to show some promise in tissue repair in general, although this is in higher doses too.
Sodium hyaluronate (aka Hyaluronic acid) - Often used for joint health, hyaluronic acid works very well, when it's injected into the site directly, a lot of supplements include a dosage that would be ideal for this (10-20mg), but when taken orally most of it is broken down in the stomach, and you actually require a lot more, and whilst there has been one effective oral trial the dose was 200mg, meaning that once again we have an ineffective dose in flexoplex. [12,13]
Boron - Boron is an interesting ingredient and not one that we see in a lot of joint health supplements despite it actually having some decent backing for treating knee pain and inflammation. It's been looked at in since the 80s and even small supplementation of around 10mg has been shown to have some positive results. We like this ingredient, it's just a shame about the rest of the flexoplex review. 
While most of the ingredients in Flexoplex have been tested in clinical trials and are generally safe, there is one major concern - the undisclosed dosage of boron aspartate. Consuming large amounts of boron can lead to adverse effects such as headaches, nausea, indigestion, vomiting, diarrhea, tremors, and convulsions. The lack of information regarding the boron dosage in Flexoplex raises safety concerns, as users may unknowingly consume excessive amounts of this nutrient. It is however unlikely that this dose will be too high by itself, but you should avoid taking flexoplex with other supplements containing boron.
As far as joint health products go, Flexoplex isn't terrible, their marketing is definitely misleading and there are certainly better value products available. But, the Flexoplex formula definitely does have a couple of decent ingredients in it and there's a reasonable chance it should help with joint stiffness and relieve pain and inflammation to a point at least. The main issue we have with Flexoplex is that there are just better options if you're looking for a combined joint supplement at roughly the same price point.
There's also the fact that it clearly underdoses a lot of ingredients and hides behind a proprietary blend. In general if you're looking for a natural supplement with anti inflammatory properties then we typically recommend FlexAgain, or if you're looking to save money, then there's plenty of glucosamine sulfate supplements that are available with boswellia thrown in that cost about $20 a month and we'd recommend one of those instead.
1 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6035477/
2 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3309643/
3 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3150191/
4 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4881293/
5 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372953/
6 - https://www.nccih.nih.gov/health/cats-claw
7 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5355559/
8 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7368679/
9 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3529416/
10 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065734/
11 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5778189/
12 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4469223/
13 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3512263/
14 - https://pubmed.ncbi.nlm.nih.gov/7889887/