The combination will not necessarily result in a "better" high as fentanyl will kick heroin right out of the opioid receptors due to 2nm Ki and they will compete resulting in a dirty/mixed feeling. I've done this combination with half a dozen kinds of fentanyl, ime the most euphoric experience was by far meo-acetyl-fentanyl by itself in nasal spray. Literally no mu activity(no sedation) but massive delta and kappa making it very euphoric and trippy. One dose lasts about two hours to baseline given tolerance and one can slip into the trippiest dreamscapes in broad daylight by just closing the eyelids..
Tez
Hey man, I really don't want any trouble, but I would really like for you to reel it in in terms of the information that you're posting. I understand that you're trying to help and I will never knock you for that if your heart is in the right place, but this isn't the first instance of you posting information that is either semi-correct, unproven or an educated guess. We simply cannot have that sort of thing here. We're talking about Heroin and Fentanyl. People die every day from this shit and we can't have anything but the absolute truth.
Fentanyl is a powerful Opioid agonists and does have a very high binding affinity for the receptors. Although it's potent, it's simply incorrect that Fentanyl "kicks Heroin right out of the Opioid receptors". You also didn't truly provide a reference for your statement. I understand you made an extremely vague reference to the receptors, but that's not enough. Fentanyl doesn't just kick Heroin out of the receptors. There is competition, but both drugs will ultimately stimulate the Opioid receptors and produce Opioidergic effects. It's just really unsafe in a lot of ways to tell people that if they use Fentanyl, Heroin will have no effect on them. I don't mean to be dramatic, but that statement could kill someone. You need to be much more careful dude.
Also, although is a little bit less dangerous in an immediate sense, it's simply not true that Fentanyl analogs have absolute no effect on the Mu Opioid Receptor (MOR). I don't know where you're getting your information, but I'm not aware of any Fentanyl analog that has "literally" no effect on the MOR.
Please be more careful man. I understand that you're still fairly new in terms of your number of posts and activity on the site even though you've been a member for a year, but please, please be more diligent in terms of your research. There is only one truth. We're not Kellyanne Conway. We don't accept the theory that there are multiple truths.