DARKNET LEAN GUIDE:

https://www.ukmeds.co.uk/treatments/pain-relief/codeine-30mg-online/

STEP 1] BUY CODEINE SULFATE PILLS + CRUSH THEM

STEP 2] DISTILLED WATER, PURPLE FOOD COLORING, PROMETHAZINE

STEP 3] MIX (+ add sucralose or other sweeteners to taste, xanthan gum for thickness, etc)

STEP 4] DRINK YOUR DISGUSTING EMBARRASSING SHIT & JUST SWALLOW PILLS NEXT TIME

PS. Codeine linctus is available in the UK over the counter. It's okay, you just need to ask your pharmacist. £3 a bottle, 15mg codeine per 5ml syrup. If you want purple add food coloring. No promethazine.

I've used promethazine and codeine, I know what it is and what it does. I also have done many other opiates alone throughout the entire range, pretty much all the way to the top minus the very rare fent analogs.
I have also used many antihistamines both with opiates and without for various reasons over the years. I still have to say that paying anything over 50 bucks a pint is ridiculous and absurd. In certain states, you can get promethazine and Codeine from a pharmacy without a prescription twice a year if you just sign a form and show ID. It's really cheap too.
I just can't imagine why someone would specifically look for promethazine and Codeine when it's not exactly an amazing combination and there are so many more opiates and antihistamines out there that do just as much or more and are extremely cheap compared to this. Just my 2 cents and people can spend or waste their money however they please.