NPP and Deca Dick... the Real Reason

So I was doing some research on NPP, some of you may know I’m 5 weeks into a high Primo, low test and mast cycle. Althought the cycle is good, i feel great, but the scale just is not budging. My goal was to hit 93kg by the end of this cycle but I am hovering between 88-90kg and its getting harder to eat more. This week I have droppes 2kg to 88kg from 90kg, it could be from stress due to the loss of a loved one last week.

Anyway, long story short, I am thinking of adding NPP into my cycle and bringing the primo slightly lower to gain some weight (ideally not water).

However, I am terrified of deca dick which robbed me of erections a few years ago for 10months. While researching I came across the following post which I will copy into the post below. Someone with some more knowledge can chime and share their thoughts on this apparent “real cause of deca dick”.

Thank you


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As I mentioned earlier in r/peds, deca dick is not due to prolactin, is not due to estrogen, is not due to progesterone, it isnt because it is 19nor.

  1. Nandrolone activates progesterone at 1/20th of the affinity of progesterone, thereby acts as an antagonist in most cases.
  2. Nandrolone has Dopamine modulation effect, similar but different to Trenbolone.
  3. Nandrolone through reward pathway modulation, can attenuate dopaminergic response.
  4. DHT is not a by product of Nandrolone. DHT can be further metabolised to Neurosteroids which have potent antianxiety and antidepressant effect. DHN does have similar metabolites but lack these pharmacology.
  5. Nandrolone and testosterone, both exogenously, in studies increase prolactin equally at equal doses (if someone can find this study I looked at awhile ago, would be appreciated).
  6. Nandrolone produces enough E1 that can be converted to E2 naturally by the body. Optimal doses to match natural levels would be around 300mg/wk.
  7. Combination of testosterone and nandrolone = induction of 3b HSD subtype 1, which is involved in the conversion of E1 to E2, thereby testosterone synergises the estrogenic potency of nandrolone. moral of the story, dont run it with testosterone.
  8. Nandrolone produces DHN as a metabolite via 5-alpha reductase, this acts as partial agonist. And competitively displaces DHT from androgenic tissue, like in the penis.
  9. DHT antagonises Estrogen in androgenic tissues and other places such as breast tissue. The lack of androgenic stimulation via DHN causes gyno symptoms to occur even with normal estrogen levels (NO it isn’t from progesterone, or prolactin).
  10. DHN can displace DHT and can partially activate the androgen receptors in androgenic tissues such as prostate and hair follicles, this can actually reverse prostate hypertrophy and cause hair regrowth.
  • The penis requires androgenic stimulation, which unfortunately you cannot get with Nandrolone. Hence why people run high dose Testosterone with Nandrolone to counteract the sex side effects, the concentration of DHT from the testosterone has to be significantly higher than DHN from nandrolone so that DHN does not displace DHT from the receptor.

  • What is actually causing ‘deca dick’

  1. lack of neurosteroid production from DHT
  2. lack of penile androgen receptor stimulation AND brain androgen receptor stimulation
  3. Dopaminergic response issues
  • What is not causing ‘deca dick’
  1. not running testosterone or enough testosterone with Nandrolone
  2. Progesterone
  3. Estrogen
  4. Prolactin

So how do we solve this issue? Im against running testosterone with nandrolone. But there is a cure!

run 0.5mg-1mg Finasteride with your Nandrolone cycle everyday. This will inhibit a good portion of DHN. Results in 50% increase in androgenic activity and optimal stimulation of androgen receptors in androgenic tissue. This cures deca dick problem, it resolves psychological arousal (due to optimal androgen receptor stimulation in the brain)

But we are left with some issues. Once you do this, your skin will instantly get oily as fuck, you’ll have acne out of no where and you lose some of the benefits of DHN. Plus, you want to fuck 24/7 and your dick agrees with you also. It seems like the dopaminergic issues resolve after the brain androgen receptors are optimally stimulated without DHN (as nandrolone will act as the parent agonist, without DHN antagonising Nandrolone).

Also, gyno symptoms would also disappear due to breast tissue estrogen receptor is antagonised by Nandrolone (no DHN to stop this).

So if we inhibit the formation of DHN, then nandrolone does not metabolise to a piss ass weak androgen in these local tissues (DHN works to antagonise nandrolones true androgenic potency as well, hence DHN actually reduces prostate size, and restores hair growth). With 5-AR inhibition, DHN does not get produced when nandrolone crosses local 5-AR tissues and thus instead would activate those local receptors much more potently. (Quote)


Here are some of the original posters sources and the rest of his post.

"Some interesting sources

[1] Sub-chronic nandrolone treatment modifies neurochemical and behavioral effects of amphetamine and 3,4-methylenedioxymethamphetamine (MDMA) in rats - ScienceDirect

“Sub-chronic nandrolone treatment modifies neurochemical and behavioral effects of amphetamine and 3,4-methylenedioxymethamphetamine (MDMA) in rats”

  • “Analysis of the behavioral data suggests that effects of the amphetamine and MDMA are dose-dependently attenuated by AAS-treatment, paralleling DA results. In conclusion, the results of this study show that AAS-pre-treatment is able to modulate the reward-related neurochemical and behavioral effects of amphetamine and MDMA.”


“Impact of Nandrolone Decanoate on Gene Expression in Endocrine Systems Related to the Adverse Effects of Anabolic Androgenic Steroids” - This one is very interesting, it shows what enzyme systems Nandrolone downregulates and which ones are upregulated. Very very important information

[3] Prolonged in vivo administration of testosterone-enanthate, the widely used and abused anabolic androgenic steroid, disturbs prolactin and cAMP signaling in Leydig cells of adult rats - ScienceDirect

“Prolonged in vivo administration of testosterone-enanthate, the widely used and abused anabolic androgenic steroid, disturbs prolactin and cAMP signaling in Leydig cells of adult rats” - “The results showed that prolonged (10-weeks) intramuscular administration of testosterone-enanthate, in clinically relevant dose, significantly increased prolactin”


“The anabolic-androgenic steroid nandrolone decanoate affects the density of dopamine receptors in the male rat brain”

[5] Increased dopamine transporter density in the male rat brain following chronic nandrolone decanoate administration - ScienceDirect

“Increased dopamine transporter density in the male rat brain following chronic nandrolone decanoate administration”

[6] The effect of sub-chronic nandrolone decanoate treatment on dopaminergic and serotonergic neuronal systems in the brains of rats - ScienceDirect

“The effect of sub-chronic nandrolone decanoate treatment on dopaminergic and serotonergic neuronal systems in the brains of rats”

Just some calculations.

lets take the following into consideration.

  1. Nandrolone is a weak substrate for SHBG. So, overall, it is a much better anabolic than testosterone, even if you take the 125:37 vs 100:100 profile into consideration. therefore, there is more nandrolone per mg exogenously administered ‘free’ to bind to androgen receptors, than is testosterone per mg exogenously administered.
  2. Nandrolone aromatises at the rate of 20% of Testosterone.

Lets say, we produce equivalent to 70mg/wk Testosterone enanthate. Taking the molecular mass of the ester into account, you would need an optimal 500-600mg NPP (or deca) per week to produce a decent amount of estrogen (but still within limits) - remember, you need neither high or low amount of estrogen for optimal mental and dick health - we also have to take into consideration the fact of how the androgenic potency of an anabolic would also act to oppose estrogen at the estrogen receptor.

Those who have done DECA only cycles and have complained about deca-dick - here is the only and only reason:

  • You didnt front load deca. so what occured is that the first 4-5 weeks whilst the ester is peaking in the blood, you arent getting sufficient blood androgen levels (levels not high enough to provide optimal androgen and estrogen signalling).
  • and/or you arent taking suffice dose. If you arent taking testosterone with your nandrolone, it makes logical sense to use more nandrolone (500-600mg/wk(

Best method is to front load… or just take NPP"


This is the answer. Most top competitors will tell you the eating is the hardest. Have you tried to drink more calories ? you could add a shake of Oats, egg white , peanut butter and whatever you can fit in the blender to bump up calories. My mate is sitting around 22 stone, he competes at strongman stuff. He told me he is up to 12 dinners a day and has to force feed himself to keep it up. He also takes silly amounts of gear.

For the NPP, I also have a stash of it sitting here, but worried about starting it. Have you heard about using proviron with deca/npp ? Over on other steroid boards I have read that it helps against the dreaded deca dick. Some guys use 50mg per day and report they get little sides. They say Mast though similar in nature does not work as good as proviron. I bought some pharma proviron to use with my NPP, but weighing up if its gonna be worth it lol.

I don’t think id have the courage to use Finasteride with the horror stories I have read, it prohibits DHT so unless one is using a DHT source, then isn’t it gonna wipe out both DHN and DHT ? I mean it sounds like it makes sense in a way, but I will let you test that theory out… Another option is to just not use that shit, period, which is what I am starting to think. I might just sell mine on to avoid any long term regrets.

I fully agree. Bulking is so much harder than cutting in my opinion.

I could try liquid calories but usually a heavy shake keeps me full for so long I have to end up missing a meal, which puts me back in the same spot. Furthermore, I’m a lacto-vegetarian so most my protein is from dairy, quorn and soya. Its been difficult but this is the heaviest ive ever been in my life, heavier than when I was eating meat and using high doses of gear mainly because my digestive system is so much more efficient now.

I’m fully with you on the NPP. I’m leaning towards scraping it all together. NPP and proviron is literally the same thing ive read about too, but im not sure if its worth experimenting and potenitally losing erections (even now they’re not the best, able to have sex without viagra but fully solid with viagra, sorry about the in depth detail lol).

All that appealed to me with NPP over EQ was the short half life hence shorter time on before cruising again. I have used EQ before and it was pretty good, the appetite increase was epic for me.

Lets see what other peoples experience is like but most likely I’ll stay away from Nandrolones during my lifting and competing career.


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I have three vials of NPP sitting around and I will never, ever use them. I bought them with the plan to do a major bulk and then I started reading more esoteric stuff about nandrolone, really deep dive stuff. That cured me of my desire to ever touch it again.

You could try a different ester of bold if EQ is too long of a timeline for you. Bold cyp is out there, though the pip is allegedly worse than anything else on earth. Or you could get some DHB. That’s getting more popular and thus more available from labs. Or just use EQ and accept that you’ll be blasting a little longer than planned. Ultimately you’ve shown yourself to be a deeply knowledgeable guy who has health as his top concern, so you know better than anyone if you’ll be able to run a longer blast without too many consequences.

Hey Iron, thank you for contributing to my thread.

This is good, another knowledgeable person who votes against Nandrolone. I think the decision is clear for me, I value my penis over more muscle.

I would use EQ now, however i only have 6 weeks of this bulk left until I transition into my cut for my show. I cant afford the appetite to linger into my cut lol I will speak to my supplier for Bold Cyp but I dont think he has it as he has never mentioned it before.


I think we all do. However, I just finished a Test/NPP/GH blast and my intention was to gain weight but the GH made it a cutting cycle. Anyway, I had some issues with the NPP and it affecting my erections but for the mast part, some cialis and/or levitra took care of the issues. I just needed to be fully rested and recently eaten. I found that if either of these were lacking, then little studhammer wasn’t cooperating.


One of my top regrets in life was ever taking Nandrolone. I tried to supplement my TRT with a prescribed therapeutic dose of only 140mg/week. That was this last summer. After 5-6 weeks I started suffering ED. Its been over 6 months since I stopped and I’m still not the same. The shame of it is that I was looking fantastic muscle and mass wise on even that small dose. It really added to my gym game but totally not worth it.


You just answered my next question, low dose NPP for joints. OK so thats out too. I certainly feel like it has correlation with testosterone but im not going to be the one to experiment.

Thank you for your input.


This makes me feel better, Im seeing that ED amongst us men is ALOT more common than I thought. Luckily ive been fortunate enough to come across women that are understanding. Also that my manhood is not in between my legs, its in between my ears (my brain and the way I carry myself, if anyone is wondering what I meant).


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No problem. If you have an libido restoring ideas I am all ears.

Time is your best friend here.

Other than that I have heard of people donating plasma to clear Nandrolone metabolites faster.

The best advice i can give is, forget you even have libido problems. Stop thinking about it and move on with your life. My problem was that I was so focused on my libido and not being able to perform that I killed my erections before they even happened. Just remember that its not the end of the world. Shit happens.



What are your thoughts on proviron with TRT? I used to cycle back in the mid 2000s but I can no longer risk it. Fast forward and I am now a licensed professional and family man and its just not worth the risk of losing my license if caught. I am on TRT and my clinic is fairly progressive with what they allow. For example they allowed me to be scripted on the nandrolone. I am currently trying to get them to script me some anavar for a brief run but I don’t think they will go for it. I was thinking maybe proviron would give me a little edge with the TRT and maybe they would go for that. I also hear it can help with libido. Thoughts?

@iron_yuppie @studhammer

Edit: Side note, I am a continually high SHBG guy so the proviron may be more beneficial to me that others.

Where do you reside, I don’t believe mesterolone is available as a prescription medication in the US. Fluoxymesterone (halotestin), stanozolol (winstrol), oxymetholone (anadrol) and nand are available as well as var. None of which are great candidates for longevity

Proviron is supposed to help with libido and even boosting fertility ive heard.

Ive never used it so i cant comment unfortunately.


I’m in the US. I’m just looking for something I can throw in for 6 weeks or so every once in awhile. My options are limited to what I can get prescribed. I also have to “convince” them a bit but wasn’t too hard when I asked for nandrolone.

Man it would be so shit to live in a country where taking steroids for personal use is a crime. Cant you just add some quick acting test? Or stock up on your trt meds and blast.


It’s a crime here too, mere possession of AAS in QLD and the NT (although I don’t live in either areas) can fetch a 25 year prison sentence. Other states are far less strict, but still posession is a misdemeanor or felony, slightly less strict than the US in some states. That being said no one gives a shit enough about it to go after people who possess AAS, they’re after the suppliers (of which there are many). Reason for the laws being strict has to do with Bikie gangs involvmwnt in the AAS trade.

@blshaw, danazol is also around in the US, but has very little anabolic potency. Some clinics offer scripts for peptides and sarms, I know of a few here in Aus that’d prescribe ME sarms if I asked for them! Peptides and sarms are kinda risky Business though given they’re relatively new, unresearched drugs

I believe most of the issues (libido wise) caused by nandrolone are neuro related (decreased serotonin and crushes dopamine, prolactin potentially plays a role too), you see the androgen displacement theory is interesting, however the amount of nandrolone you’d have to take to fully saturate the AR would be absurd, therefore I don’t believe the DHT → DHN displacement theory because if you take test + nand theres a very good chance the AR isn’t fully saturated thus circulating DHT will still increase.

Granted I’ve taken nandrolone briefly at a low dose and never had any issues, as a matter of fact nandrolone made me feel amazing while I was on it, shows how individual these things can be. Either way, I don’t intend on ever using the stuff again, the drawbacks aren’t worth it (very harsh on endothelial cells in vitro compared to test, neuro sides, prolactin sides, and it doesn’t particularly do anything test can’t)