Is no secret that for a long time many people in the bodybuilding community (from professional athletes to the regular gym rat) have given some sort of credit to pain killers or narcotics, specially opiates, as being an integral part of their general "supplementation protocols", specifically when it comes to recovery. I know, it may sound stupid to you as it does to me, but there's people out there that swear by it and I don't judge them, because these type of drugs have a way to make you believe things that are not true. Thats why so many fall prey to narcotic drugs.
The general thought behind this erroneous concept is that: "The more relaxed I am during my resting period and the better sleep in an REM state, the better recovery I will have and that will render better growth". Well, in theory thats correct, but if your way of obtaining this is through pain killers or narcotics, I'm sorry to let you know, that you are actually achieving the reverse effect and that is called CATABOLISM!
There are many studies that grant or give some sort of benefit in muscle recovery to drugs like acetaminophen, aspirin and medicines in the NSAIDS family. But when we talk about narcotics, there is no scientific evidence that this type of drug will help in a substantial or enhanced way to muscle recovery. The only credible (better yet incredible) evidence regarding this matter comes from anecdotal evidence, better known as "bro science".
Don't get me wrong, there's a purpose for this drugs and if your doctor with a real license (not a "doctor wanna be" with a 22" bicep) prescribed you something like this, he/she knows why he/she did it. I'm not talking about legitimate medical issues, I'm talking about bodybuilding/recreational usage. If you are reading this and your doctor put you on some drug of this kind, well... listen to your doctor, what the fuck do I know about anything anyway. I'm talking about the geniuses who pop these pills thinking is helping them to get bigger and better just because they feel recovered and rested after taking them.
There is many, many, many scientific evidence that prove that narcotics will have a deleterious effect on muscle building, but somehow people insist that they do help in some way. The problem with this is that many people, short in the brain department, are so desperate to obtain gains and have this wrong mentality of "anything and everything it takes", that they end up doing things like this and the end result is usually not a pretty one. People who insist in this practice usually end up with narcotic addiction problems, with severe health issues and death is always a big possibility.
Is a known fact that inflammation is an important factor in muscle development. Thats why supplements like arachidonic acid, that work through inflammation, are utilized to build good amounts of quality muscle. But when people use narcotics such as: Percocet, Codeine, Hydrocodone, Vicodin, Tramadol, Ultracet, Morphine and of course the infamous Nubain (which according to the May 2000 issue of MuscleMag International, 6 of the top 10 Mr. Olympia contenders use Nubain on a regular basis to be more relaxed and sleep better before competition) something very intresting happens and there's a study that proves this point.
Here's the link:

https://www.nature.com › aps2007138
Morphine enhances purine nucleotide catabolism in vivo and in vitro - Nature

There is a reason why muscle pain or inflammation are important, specially in muscle building. Muscle pain or inflammation is, in simple words, a double signal to the brain. One signal is for you to stop, eat, and rest. The other one is so it can send the proper help to the affected area for repairs. If you are taking the proper supplementation, having the proper nutrition and the right amount of rest, chances are you are going to have good protein synthesis and recovery. But if after a hard session in the gym your solution to get a good night sleep for recovery is, lets say a Percocet, well... you just committed self sabotage. Let me tell you why. Just like we know we have androgen receptors and estrogen receptors, we also have hundreds of other receptors through our system and among them is one that is called the opiate receptor. When a person makes use of a narcotic opiate what happens is basically that the signal to the purine nucleotide gets blocked, and that purine nucleotide is nothing else than the general manager for all cellular regeneration throughout the body, in other words, you stay catabolic because you blocked the call, from the main office, to the construction site and the workers took the day off. Theres no cellular regeneration and no recovery. You may say; but I'm on TRT! Well, that testosterone will just get metabolized and excreted if you stay on those drugs for a prolonged period of time, because you are blocking the use of it in terms of cellular regeneration. In the same study, was proven that when a opiate antagonist, a blocker at the receptor level called Naloxone was administered, the purine nucleotide was reactivated soon after. In other words the recovery and cellular regeneration started once the opiate was blocked from the receptor.
This aspect may be confusing for some who after using opiates may come to believe that it helped them in some sort of way to recover better, but that is just an illusion. Soon enough the person will realize that the progress has come to a halt. Not to mention the fact that pain tells you when to stop. Many are the stories of people who've been injured while using narcotics and exercising at the same time. Yes, of course we should want to push the envelope to the max, but always with a clear head and all your senses fully activated, including the capacity to feel pain, so you know when to stop and dont do more harm than good. I wouldn't advise nobody to get in a squat rack with heavy weights while using some sort of narcotic, that's just plain crazy for me, but people seem to be stupid enough to do shit like that. May the gods enlighten their brains.
Others claim that opiates (synthetic or organic) helps them do more and better cardio workouts, when the reality is that is proven that all opiates have an effect that is called: Opioid Induce Respiratory Depression. In other words you cannot breathe right. You develop shallow breathing and the ratio between oxygen and carbon dioxide gets messed up. During hypoventilation, the body can’t adequately remove carbon dioxide. This can lead to poor use of oxygen by lungs. The result is a higher level of carbon dioxide and too little oxygen available to the body, and we know how important is oxygenation in muscle building. Actually the great majority of people who have died from over dosage of narcotics, died because they suffered respiratory failure. Still some people claim that they can stay in the step climber for two hours because of these drugs. Yep, people can stay in a step climber for two hours, but absolutely not because they had enhanced endurance, is simply that they were high as a fucking kite, and when your are high, watching a turd float might seem like a good way to invest your time and anything is enjoyable. But "enjoyable" is not the same thing nor has the same definition as "effective" and we are looking for effectiveness. Effectiveness in the long run will yield enjoyable results, while enjoyable in the short run will not yield effective results.
If some meat head tells you that narcotics are good for recovery, thats exactly the type of person that you should avoid if you are truly serious about your health. There are far better and effective options to develop a good recovery protocol. There are things like:
- Melatonin
- Teas
- Antihistamines
- CBD Oil (Even though is thought to raise estrogen levels, still is way better option than opiates and tons of research shows that it possesses healing properties.)

Opiates or opioids, however you might like to call them, they have their purpose in the medical field as an excellent pain killer for those who really need them because of severe injuries or painful diseases and that might include people injured from all sorts of sports. But for muscle building... we want and we need the pain. To use this kind of drugs as a way to enjoy our workouts better or to get better sleep seems to totally defeat the purpose. To win the fight against ourselves is what actually makes us strong. Self sabotage is the strongest strategy our weakness have against ourselves.
Keep on rocking and be safe!