My friend, you can stack anything with anything, and people will share different stories and side effects. However, there is an old rule that two 19-nor steroids (nandrolone and trenbolone) should not be stacked together due to potential side effects. All 19-nor types can increase prolactin, and while tren and decca have negative side effects for me, npp (which has a quicker release than decca) has no negative side effects at all. I cannot explain the scientific reasons for this. If you want to try stacking these steroids, be sure to have the correct ancillaries on hand to manage prolactin, such as cabergoline or prami. Stacking these steroids together for your fourth cycle is a significant step, and I have been cycling for over 10 years and have never had the courage to stack them together.
If you want a similar stack with less risk of side effects, I suggest a combination of test, tren, and equipoise, such as 500mg of test, 600mg of eq, and 300mg of tren (as a little tren goes a long way). Alternatively, for a bulkier look, try 600mg of test, 500mg of nandrolone, and 800mg of eq. Adding proviron to any stack can minimize side effects, and keeping an eye on your estrogen levels can help manage prolactin issues.
If you have any questions about the finer details of your planned stack, feel free to ask in the comments. However, please note that my knowledge is based on personal trial and error and may not always match scientific research. What works for me may not work for you.
I didn't try Tren until many years after my first cycle. If you want to increase strength and become leaner, it can be helpful, particularly for strength gains. It is advisable to start with 150mg of Tren per week (EOD) and split it up based on the ester's half-life. Start with Tren Ace to assess side effects, as it will leave your system quickly if you can't handle it. Always use Caber when running Tren and avoid Prami, as it's not effective. You can even start with a lower dosage of Tren depending on your goals.
It's essential to have a clear understanding of your goals. If it's strength or powerlifting, Tren is an excellent choice. For maximum muscle building, it's okay. For contest preparation, it's very potent. A cycle of 150mg of Tren per week, split EOD, and 400mg of test per week is very potent. If your hairline can handle it, you can add 200-250mg per week of Masteron to have an incredible cycle. Personally, I don't experience many side effects from Tren, but some night sweats are intense. Additionally, sex drive increases significantly. You may find yourself thinking about sex all the time while on Tren. Depending on the dosage, endurance may decrease, but it's not debilitating at low doses. Minor changes in hairline may occur, and strength increases significantly. Other positive effects may also occur.
Combining Nandrolone and Tren together is risky from a side effects perspective. It's better to use equipoise or an oral AAS instead.