I am honestly having a hard time deciding. The thing with Tren is once you use it, you are going to want to include it in all cycles if you can stand the sides. Even if the sides drive you to the breaking point you may still run it because of the results. Let me think on it a bit and let Voxide, Renz, and Genetic Freak give their input. .
Have done Trenbolone, but it was a while back around 2006 ish'.... But from what I can remember We used Tren Ace' and found it to be quite powerful stuff... Aggression was through the roof, great for training but you have to be aware its nobody else's fault, so if you can't keep a check on your aggression maybe its not for you....
The sides I have found are person dependant, plus it depends a great deal on what else you combine it with.. in my opinion..!!!
Tren being a 19-nor therefore a Progestin, so it can raise Progesterone, which can in turn lead to raised levels of Prolactin from the Pituitary.... (man-boobs)....!!!
Progesterone gyno cannot develop though in the absence of Estrogen.... Tren can't convert to Estrogen but Test can through aromatisation... Hence don't go mad with the Testosterone when combined with Tren...
We found no more than 350mg/weeks seemed to work better for us... Any more and we didn't see many benefits, plus the sides did tend to kick in over 350mg/week...
Also we did think that combining another 19-nor like Nandrolone (Deca) seemed to greatly increase the negative sides..
Back to the original question of when to include Tren to a cycle...?
When .... "If"...? might be more appropriate.. There seems to be a common misconception of always wanting to increase after each cycle... More doesn't necessarily mean more gains, it will mean more sides, if you are unlucky.. With 19-nors you do get a significant size increase, but a lot of it is water retention, so you will lose some or most of it when you come off.. So you might be inclined to think what's the point....
You don't hear too much emphasis on increasing Carbs & Protein....
More Calories will increase mass, more calories plus more intensive exercise will greater increase mass...
Greater knowledge of basic cycle planning might be a better option.. There are only three options for a cycle: Testosterones, 19-nors, & DHT's ..... Each can have a place if used together synergistically for their benefits when combined together...
You might consider Test @ 500mg/week as a first cycle..... (Testosterone)
Test + Dbol 20mg/day week 1-6 ........ 2nd cycle (Testosterones)
Test + Deca .............. 3rd cycle (Testosterone + 19-nor)
Test + Boldernone .............. 4th cycle (Testosterones)
Test + Deca + Dbol 20mg/day ........ 5th cycle (Testosterones + 19-nor)
Test + Boldernone + Winstrol 20-30mg/day........... 6th cycle (Testosterones + DHT)
Test + Trenbolone ............... 7th cycle...... (Testosterone + 19-nor)..... Maybe low dose winstrol as a DHT to check Estrogen ..??? Maybe lower the Test to account for the extra Winstrol....
The options can be many, I haven't included Parabolon, Masteron, Primobolan, Proviron, Oxymetholone, Anavar, where do you stop, or do you need to go beyond 500mg/week........?
increase your food intake and lift more might be more appropriate .......
I know we've all done it, but is there any need...?
My 2c.....