Not much of a science guy here but from personal experience via my colleagues, they have to also supplement with estradiol because the deca solo only converts to a different estrogen I think called estrone. Estradiol they said is what is the protective estrogen for good health. The like deca only but have to supplement with estradiol and make sure their e2 is good with monthly bloodwork

Decade only cycle? Not if its gonna be longer than 5 weeks.
Why? Because you run out of estrogen. Only reason.

Found this online below! I'm not preaching it.. Soo.. No need to yell or argue at me about it! Just interesting info....

Has a few interesting science links behind it:

"There are a few people who do Deca only!!" Although they run finasteride when doing so!
Why take finasteride???? 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.

So how do we solve this issue? Im against running high 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).

Soo.... 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.

I know.. I know.. People ask:
How will cutting out DHN increase androgenicity if there is no DHT in the system (no test). Presumably because Nandrolone itself is an agonist at DHT receptors?

Because its the same androgen receptors everywhere. there is nothing special about androgen receptors in 5-AR expressed tissues (like hair follicles), other than that those particular tissues have 5-AR enzyme expressed - So when a substrate for 5-AR comes along to those particular areas, the 5-AR will react and reduce the androgen (testosterone in this case) to DHT. DHT binds tightly to the androgen receptor, and doesn't really like 'moving' away from the area it has been created. Here, DHT has 2-3x the binding affinity than testosterone, so it tends to take preference for the local androgen receptor, and exerts 10x the signalling, once bound.

Every anabolic steroid has an anabolic and androgenic profile. Trenbolone can bind to the same receptors as DHT, and stimulate it. Same as Anavar. Except Anavar is pretty weak in doing so.

When you take Nandrolone. it will float around and come across these tissues where 5-AR is expressed. here, nandrolone will reduce to DHN, DHN will bind to the receptor. This lowers the androgenic potency of nandrolone because of DHN's competition for the receptor - DHN is a weak androgen, nandrolone would still exert its anabolic response in muscle tissue (for example). When 5-AR is inhibited, nandrolone's true androgenic potency comes to light, and is able to bind to these receptors without competition.
Boom.. No deca Dick!!

Some interesting sources

[1] https://www.sciencedirect.com/scienc...6643280800003X

"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."

[2] http://onlinelibrary.wiley.com/doi/1...9.00439.x/full

"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] https://www.sciencedirect.com/scienc...6007601500014X

"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"

[4] http://onlinelibrary.wiley.com/doi/1...0.01402.x/full

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

[5] https://www.sciencedirect.com/scienc...04394003013685

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

[6] https://www.sciencedirect.com/scienc...06899305003641

"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.
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.
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)

Finally, people will shout out! What about "Prolactin" issues? Well, the whole idea of using a dopamine agonist initially was due to some prolactin issue people were assuming they were encountering. But it seems like those who encountered such problem (along with high estrogen) were the people who combined "testosterone with nandrolone". As nandrolone and exogenous testosterone increase prolactin almost equally. Perhaps the combination causes a synergism in the increase of prolactin?

But, as some of the studies i quoted, it seems like nandrolone (along with trenbolone), alter dopaminergic transmission . And by using a dopamine agonist, it may negate any problem that this 'disbalance' could cause.

Whats up fellas lately i been seeing the usual deca or npp but also deca cypionate and eq cypionate is this better than traditional deca ? And are you supposed to go by the dosage guidelines of regular deca 250? Thanks for the knowledge

I know... I know... Before you scream crazy at me guys! I'm just the messanger not the culprit!
look at this case study from "ANABOLIC DOC" below & links from coach's & gurus! I may give DECA only or DECA & only 100mg of TEST CYP a week a try too!

https://youtu.be/8AisKoiIRmg

https://www.taeian.com/deca-base-cycle-no-testosterone-no-sides/

https://www.reddit.com/r/PEDsR/comments/812n58/nandrolone_deca_dick_real...

I just got off a similar cycle of 500 test 275 deca total weekly pined to times per week and 50 mg anavar 25 twice a day at 25 mg with a kick start of npp and a taper of npp. My right shoulder had been bothering me so I delayed the cycle for months. Finally just did it anyway and within less than two weeks if felt fine and still does to this day. Had good results for conditions I was under. Was happy with it also tapered with test prop and started my pct 3 days after last injection. Feel like is going pretty well. Also was on 7 IU HGH split 2 times per day. Water retention wasn’t bad. No real noticeable moon face at those levels

Both deca and npp do me great. I do as you do also a 2:1 ratio usually 500:250 600:300.. for me it really gets me looking full and gain much more than test alone. My first cycle way back in day before I knew anything was deca Norma the blue in whites. Shut my ass down hard haha did make some gains but was not a good experience what so ever. Npp I prefer over deca because I like my gear in and out except for the test. I like mixing npp with cyp because it helps smoothen it out. Npp for me is pretty painful, deca is very smooth imo. Nandrolone is very responsive for me so I don't have to take in very high dose typically 300 a week npp

Decca is fine and it's great for joints and connective tissue, but I wouldn't use it without Test. Also watch prolactin levels.

Something I've really noticed lately with NPP is with some Labs I get a slightly winded lethargic feeling when using it and other labs I simply don't - almost halfway between the tren winding lol Anyone else get this too?

Deca is garbage