I've had some crap Kratom. There are only two vendors I will purchase from and each for different products. Honestly, once you find the vendor that works for you, quality stops being a problem. I've noticed the type of grind greatly affects how much I need and the effects. I just posted about this. I have no idea what causes it, but I can only feel the Kratom if I consume it in a micronized powder form on an empty stomach. In fact, the guy I buy from I only buy his deveined Thai or Maeng Da and with both I only require 1.5 tsp (yes that's tsp.) to get a mild effect ad 2 tsp for a moderate. I've been a kratom connoisseur consistently for over 6 months too and off and on for 6 years. However, if I try any other form, even just a fine powder, it has nearly zero effect, unless I take super high doses and even then it's miniscule. Was the grind micronized? Believe it or not? Also, I haven't felt the effects of an Indo in over 4 years from one of my first vendors I tried. Recently, none have been potent enough for me to waste money buying more. Stick with Maeng Da. You can almost never go wrong with that strain. Super potent.
I can attest to kratom WD symptoms while still taking a script, not Subutex though. I thought my oxy script would stop the kratom WD's, but it didn't. Something I've picked up on over the years of reading about kratom is that people that use kratom to detox from scripts and then CT kratom later, STILL end up going through severe WD's very similar to their opioid pills. However, folks that never used kratom to discontinue a pill have minimal WD when they CT. Not that they are non-existent, but they are minimal and short lived. One thing I do know for sure, if someone uses kratom to discontinue a script (cannot claim a natural opiate, as I've read few stories about this and haven't personally experienced it) they should not CT the kratom, unless they like pain. It's best to taper slow and using only the amount daily necessary to keep WD's at bay. I also know firsthand that taking calcium, magnesium, and potassium supplements (minimum RDA value daily and then eat large quantities of potassium containing foods, b/c you cannot consume too much from a food source like you can from a supplement) during WD, that this will GREATLY reduce WD symptoms. I believe WD symptoms are magnified due to an electrolyte imbalance and dehydration that is very common in kratom consumers. The aforementioned supplement regimen has also been helpful combatting tolerance issues as a result of frequent kratom consumption too. I don't know why, but I know it's worked on two separate occasions. I can consume 1.5 TSP, not TBSP, per serving and receive benefits.