Please give some more info. Short googling says Tren/Nand actually lowers prolactin instead of increasing it. What the fuck?
That's correct, nonaromatizable androgens (e.g., Tren, Mast [drostanolone]) lower prolactin rather than increase it.
Aromatizable androgens (e.g., Test, Nand, MENT), including nandrolone, tend to lower it when
estrogens are sub-normal/low-normal but can increase it when estrogens run moderately-high/high.
Here's some more info:
Article on distinguishing progestins, prolactin, and progestagenic androgens (e.g., Tren, MENT, Deca) & SERM vs. AI logic [by Type-IIx] – with special emphasis on the "Anabolic steroids increase serum prolactin" section.
De Las Heras, F., & Negro-vilar, A. (1979). Effect of Aromatizable Androgens and Estradiol on Prolactin Secretion in Prepuberal Male Rats. Archives of Andrology, 2(2), 135–139. doi:10.3109/01485017908987305
Van Der Gugten, A. A. (1971). The effect of 1-(morpholinomethyl)-4-phtalimido-piperidindione-2,6 and drostanolone propionate on the plasma prolactin concentration of oestrone-treated orchidectomized R-Amsterdam rats. European Journal of Cancer (1965), 7(6), 581–582. doi:10.1016/0014-2964(71)90066-1
Sodi, R., Fikri, R., Diver, M., Ranganath, L., & Vora, J. (2005). Testosterone replacement-induced hyperprolactinaemia: case report and review of the literature. Annals of Clinical Biochemistry, 42(2), 153–159. doi:10.1258/0004563053492784
Segaloff, A., Weeth, J. B., Cuningham, M., & Meyer, K. K. (1964). Hormonal therapy in cancer of the breast.XXIII. Effect of 7α-methyl-19-nortestosterone acetate and testosterone propionate on clinical course and hormonal excretion. Cancer, 17(10), 1248–1253. doi:10.1002/1097-0142(196410)17:10<1248::aid-cncr2820171005>3.0.co;2-a