Pull back. The blood rushes in. I got it. Slowly push the plunger? I want this to last. Pull it back out again, the blood swirls back in. Now. Squeeze. This is what they mean by a rush. It rushes up my arm in tingles. Then it hits. Shit. It is like a mini explosion of pure pleasure.   Everything is blissful and beautiful psychologically. I love everything. It is pure joy to  be alive, to have a body; briefly that is the only awareness.

Depending on the quantity and quality this echoes a little or a lot. Sometimes it is there for hours. Sometimes it fades to just feeling amazing.

It is sensual. All your nerves are on fire and just having someone run their fingers along your skin feels delicious. It isn't really sexual. I think it is simply that the intensity of the experience lends itself to being described that way. It is actually difficult to orgasm while high on Heroin. Most people can't, but a woman can, with determination. Wow. Wow. Wow.

If you are doing nothing then you tend to "nod off" which is definitely similar to the dozing state after you wake up. When really stoned dreams feel very real (lucid) and often you are disturbed by replying. Woken up by your own talking, it can be quite confusing that there is another reality.

Most people tend to try to be inactive to encourage this state. Those of us with backwards brains (ADHD users are often talkers on heroin) like to do things like read or talk to get into an "awesome" conversation. I used to take a little bit to do school work because it helped me focus. Anyway I am getting off the subject.

This is when you are "high" on heroin. This gets rarer the more you use regularly as your tolerance rises.
All pressumimg you did an adequate yet safe dose of decently pure heroin (diacetylmorphine) or similar opiate (e.g prescribed Dilaudid or Morphine)…and NOT the so called “white china” - much of which (nowadays anyway. Before white China used to be A grade Heroin until fentanyl came along) is fentanyl from China & is responsible for the sharp rise in OD's recently… Look into it / basically don't touch the fent or fake “white china” aka easy to make in a lab fent powder. Btw fent isn't always white… However the chineese gov despite proof that the majority is coming from there refuse to admit it. Also note that just because it's not white it doesn't mean it's legit heroin either. I've seen brown , purple and grey heroin being passed off as fent too.
Anyways…ive written an answer on the whole fentanyl thing, it coming from china, chineese gvt refusing to recognize the problem & a sharp rise in overdoses as fent is cheaper to produce , smuggle etc than Heroin.
And most importantly so very much stronger milligram for milligram - but despite being stronger it's lacks a certain enjoyable feeling that most other opiates have. And it doesn't last long… So if me or many prior or currently addicted people could choose an opiate to fix up with I would pick uncut heroin or morphine any day to shoot up over fent. That for enjoyment and safety wise as well. And it keeps you well much longer/isn't as fiendish. It's very easy to OD on fentanyl and the withdrawals also start faster and are often worse. However douchebags continue to make and sell fentanyl -_- .
But yes…
For me it feels like I'm in my living room, wrapped in a cosy blanket by a fireplace looking outside and its like -50.
Imagine that cosy feeling you get from that x100.
You're worst enemy, war, famine, corruption & all the problems of the world dont seem so bad now.
You kind of just want to lie there and enjoy it. Maybe have a little nod off if you want. You also feel a little itchy too but in a good way. The itchyness and relief you get from mosquito bites - the itchyness you get is similar to that and the relief you get when you itch mosquito bites. But it's not like a bad way like I said aka like meth where you may feel bugs crawling under skin.
If you fall asleep on it you will have the best night sleep of your entire life.
You may feel a little nauseated your first time but if you puke it actually feels good.
Everything that bothers you is gone and you feel so happy in the moment and don't want it to end.
Unlike MDMA I don't feel as talkative on it. Well not as much as MDMA. Don't get me wrong though I'm energized to work my crappy 12 hour shift mundane job - that shift flies by (if I'm on a moderate dose. Higher dose I wouldn't recommend unless you want to be fired or have a tolerance) . Without it that job makes me want to kill myself lol. And of course any social interaction is somewhat improved and social anxiety is reduced on opiates/heroin... But hey that's Heroin for ya.
I don't feel that it has a psycadellic effect tbh.
Just sedation, relaxation and pure euphoria/bliss.
Don't reccomend trying it though. Especially not injecting it (Its a whole other level - Better yes. but what comes with it is the chance of a serious addiction. It feels so good that it's hard to stop and before you know it you've sold everything to carry on feeling good and not face withdrawl and are at rock bottom.).
What comes with the injecting vs snorting, popping etc of many opiates one being heroin is they give u an extra rush. An amazing rush. As soon as the needle is plunged its like an orgasm x100 then that mellows out after usually a few mins into the the rest of the high described.
The reason for injecting being superior & most effective (also most dangerous) is because it going right into your bloodstream to your brain in a matter of seconds at max bioavailability (with the exception of oxycodone and some other opiates - with those injecting them actually carries less bioavailability surprisingly.) therefore giving you a nice warm hug rush which will make you never really want to go back to taking it any other way but with a needle.
Snort it or smoke it if you MUST . But even then just stick to weed. Not as bad for you and no where near as addictive.
Like its seriously addictive for a reason. It's because it is the best feeling ever ...
... Especially for those dealing with some form of emotional or physical pain… while it lasts anyways… But then coming back to the normal world where you dont feel like the best you have ever felt anymore can be pretty damn hard.
Eventually if and when your addiction gets really bad you can forget what I said above about what it feels like as at this point it will just make you feel normal… Or not get you nearly as high as I just described above.
It has been shown to hardwire and change the reward circuit in your brain significantly. It stimulates it so much that things like love, excitement, energy and more aren't felt as strongly by the brain of an ex opiate user.
This whole answer goes for any strong opiate when injected from Heroin to Hydromorphone to Morphine...(Don't support crappy, cheap to make & smuggle fentanyl. Only reason it's slowly becoming more popular. In terms of effects it's more dangerous and feels less euphoric but is sadly still an opiate.)
Of course each opiate has their slight differences (e.g mg for mg each has a different potency. And more.) but at the end of the day they all feel kinda similar when taken in their relative dose as they are all opiates.
They're the perfect drug for many. Just too perfect - And anything usually to good to be true usually is. Hence the downward spiral of heroin addiction if you use it often enough just for a few weeks. At first it is the perfect drug. There's no hangover, you aren't cracked out like stimulants, not shy, calm, cool,. a little pin eyed but it's literally the perfect drug . Heroin or morphine which u can obtain in pure form more often and is safer to inject.
Then eventually after some time your body starts to become tolerant/dependent/adjust to it - And if it gets bad enough your doing it just to feel normal or get out of bed. You successfully quit then try doing it once in a while & most can't use just once already addicted. If you've never used it before and are going to use it anyways this is why you should only expirement with it and not use it more than a couple times (& that's if you must)….
That or if you are in pain. I don't support drs who completley refuse to prescribe opiates for people with chronic pain. Sure try other meds first and opiates last but for many it's honestly the only thing that works…. Go through chronic pain yourself before questioning this. It's no walk in the park physically ofc or emotionally…. I've tried alot of medications including medical marijuana too and opiates honestly were the best for pain… If you have the discipline to take them as prescribed. Which I know I can't do but know many who can and have… soo im clean yay but also suffer with chronic pain now.