There are a few versions of Zyflamend marketed for different things, there's not much difference between them, but we're looking it's use for joint function.
New Chapter Zyflamend has a couple of ingredients that are known for their anti inflammatory effects, the catch is that they're not dosed nearly high enough to be as effective for joint health as we'd like. Turmeric is great as is Ginger, the problem is that the active ingredients curcumin and gingerols have to be in doses that are three times or higher, in the case of ginger its more like 15 times what is in Zyflamend to be effective. As for the rest of the inclusions in Zyflamend there's some potential, but generally speaking there's not a lot in here. Zyflamend could relieve minor pain or soreness, but isn't going to do anything much for joint pain relief beyond that.
And when we compare Zyflamend joint support that to some of the best joint supplements , which do contain the studied dosages of many of the core ingredients, plus in some cases half a dozen more ingredients that have been shown to effectively reduce joint pain, then it really isn't much of a competition as to what you'd be better spending your money on.
NB There are a couple of other Zyflamend branded joint products with minor formula variations. However, the differences are normally within 10/15% of the ingredients list of the version that we're working from, Zyflamend Herbal Pain Relief. There is also a prostate product branded as Zyflamend by new chapter, however we are not covering that supplement or it's efficacy in prostate related maters.
The customer reviews of zyflamend are actually surprisingly positive, the product goes back a long way and their have been several versions, but all throughout they've been consistently positive on Amazon, with the exception of more recent reviews complaining about product changes. We're actually quit surprised to see this considering similar supplements get far more negative ratings and the contents should have similar effects on health joint function. Could this be the result of an on the ball marketing team encouraging positive reviews? Well new chapter are owned by proctor and gamble so it wouldn't be a surprise to know there were dedicated managers for new chapter reviews. This does make negative reviews of Zyflamend difficult to find.
(Personal aside - my own joint issues of moderate severity were notably worse using Zyflamend vs FlexAgain).
Is Zyflamend Safe?
Zyflamend was deemed to be safe in trials and generally speaking customers report very few if any zyflamend side effects.
Is Zyflamend Good For Arthritis?
A quick review of Zyflamend Whole Body's ingredients would suggest that it's underdosed for both OA and very under dosed for RA which generally requires higher amounts.
Holy Basil 150mg - Tulsi or Holy Basil contains the active ingredient ursolic acid, currently most studies have been done with doses between 300 and 3000mg as concentrated extracts and up to 14g per day for the standard plant.  Whilst Holy Basil has been shown to be effective in multiple trials, for inflammation and even further medical therapy, meanning the 150mg in new chapter zyflamend is too low.
Turmeric 100mg - Turmeric's active ingredient curcumin is particularly good for healthy joint function and reducing inflammation, however, curcumin is normally dosed at 500mg for inflammation and it typically only makes up less than 10% of standard turmeric meaning that new chapter zyflamend doesn't have a high enough dose to be within the ideal ranges to reduce inflammation. 
Ginger 75mg - Ginger again is another good ingredient at nowhere near the correct dosage in zyflamend for joint support, most studies have it's effective range at 3grams although some extracts such as eurovita 77 can be effective at 255mg, however, it's still far more than is in zyflamend. 
Chinese Skullcap 100mg - Chinese skullcap is generally not very well backed in humans only really in mice. 
Lemon Balm 85mg - There's some scientific backing for using lemon balm for inflammation,  but it is relatively limited. It's more well backed as a sleep aid.
Camomile 75mg - Chamomile is cited as having anti-inflammatory effects, and is generally backed as an effective topical, and particularly for throat inflammation , we couldn't find much information to suggest it's effective as a supplement for joint health, or what the ideal dosage would be.
Valerian 40mg - Valerian root bark is normally used as a sleeping aid, valerenic acid and valerenol (compounds within valerian root) have been shown to impact the GABA receptors which aid sleep. It doesn't really do anything for joints though.
Hops 75mg - Similar to Valerian root, it's good for sleep and anxiety etc, doesn't really do much for healthy inflammation response though.
Zyflamend may well be beneficial for the body's healthy response to other conditions, however it's purpose as a dietary supplement for joint support seems relatively unfounded. Whilst it definitely won't do any harm to a relatively healthy inflammation response, most of the ingredients are too low on the dosage front to be at their most effective.
There are much better options for joint supplements out there, which have been designed specifically for joint support rather than being a repurposed supplement with a few changes. Zyflamend seems to be an odd mix between joint supplement and sleep aid, but we wouldn't recommend it as a go to option for people seeking joint support.
1 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376420/
2 - https://www.arthritis.org/health-wellness/treatment/complementary-therapies/supplements-and-vitamins/supplement-and-herb-guide-for-arthritis-symptoms
3 - https://pubmed.ncbi.nlm.nih.gov/11710709/
4 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6271178/
5 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3870089/
6 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2995283/