ResearchSafe

Mild scarring and testosterone drop after 4‑week NPP cycle

Posted by kayla_s in Safety & Side Effects - 2 points, 3 comments.

I started a 4‑week cycle of nandrolone phenylpropionate (NPP) for lean gains and a bit of joint relief. The first week felt good – a few days after injection I had a mild ache that went away by day three. By week two the injection site started to look a little red and swollen, and I noticed a small lump that didn’t go away after a day or two.

I stopped injecting there and switched to the opposite thigh, but the lump still stayed. After the cycle I did my routine bloodwork and my free testosterone was down about 30%. I think the injection‑site inflammation and the testosterone suppression are linked.

I learned that using a fresh 25‑g needle each time, rotating sites more aggressively, and applying a light compress after injection can reduce the risk of cyst formation. Also, checking testosterone and lipid panels every other cycle helps catch suppression early. I haven’t done it since, but I’m keeping an eye on my levels and staying mindful′ of the injection technique.

Comments

  • ivy_mobility: I got a similar reaction when I ran a 4‑week NPP cycle a few years ago. The first injections were fine, but by week two the thigh started to look swollen and a small lump stuck around for almost a week. I switched sites and added a 30‑second compress, after that the swelling eased, but the lump stayed until after the cycle ended. My free testosterone dropped about 25 % too, and it only?> Recovered after a 4‑week post‑cycle break and a single dose of a low‑dose aromatase inhibitor. I was surpris
  • kayla_s: The rebound you saw after a 4‑week break and a single low‑dose aromatase inhibitor was pretty quick, so I’d be curious which AI you used and at what dose. Did you notice any joint or mood changes after the rebound? Also, did the AI affect your pain relief from NPP?
  • greg208: Not gonna lie, I had a similar lump after my first NPP week. The compress helped a bit but my testosterone still dipped. I did a short break and a single low‑dose anastrozole after the cycle and saw T bounce back in a few weeks. Glad yours worked.
  • kayla_s: Honestly I stuck with the compress and still saw a dip in free T, so I’ve been waiting to see if a low‑dose anastrozole can help like yours. What dose did you use and how long after the cycle did your levels rebound?

Community discussion - research and educational context only. Not medical advice.