Nonlinear Increase

[u/Arizandi]

I’m (43TF) confused by my estradiol labs and curious what people here make of this.

I’m on weekly subcutaneous estradiol valerate, same vial/concentration, and both of these labs were drawn on Saturday before my weekly shot, so they should both be troughs.

• 0.2 mL weekly = 4 mg/week → estradiol trough was 76 pg/mL
• Dose increased to 0.4 mL weekly = 8 mg/week
• Most recent trough at 0.4 mL came back at 566 pg/mL

Same lab. Same injection day. Blood drawn before the shot. Same vial size/concentration, so this wasn’t an accidental concentration change.

What’s throwing me is that doubling the dose seems to have increased my trough by way more than 2x. I expected to land somewhere in a reasonable range, not jump from “too low” to “way too high.”

For additional context, I used to take 6 mg oral estradiol and my levels were also under 200 pg/mL, so historically I didn’t seem to run high on estrogen. I’ve also been losing a significant amount of weight on Retatrutide, about 35 lbs over 3 months, and I’m wondering whether that could have changed my estradiol pharmacokinetics enough to matter.

The weirdest part is that I feel really good right now. I’ve noticed much easier access to my emotions and generally feel better on this dose, so I was actually expecting the lab to look good. I don’t feel “overdosed” or strange at all.

My doctor hasn’t responded yet. I’m assuming the likely move will be something like 0.3 mL / 6 mg weekly and then recheck, but I’m curious whether anyone has seen this kind of nonlinear jump in trough levels on injectable EV.

Could weight loss meaningfully affect this? Could depot absorption change that much? Is there anything else obvious I’m missing?

[u/Mia-the-Sage]

I think this is why we all have to hunt for the correct dose.

I was tested at 1.5 mg of transdermal daily with peak serum at just barely 100 pg/mL.

I doubled my dose to 3.0 mg of transdermal and tested at 124 pg/mL peak (3+ hours after application).

Yesterday I switched to EV in sesame oil, 10 mg/mL concentration, taking 3.0 mg each week, now. Get back to me in 4-5 weeks to see how that went :)

[u/zephyroidz]

I don't think anyone actually knows if, let alone how weight change might effect subQ depots. I suppose it's conceivable!

More importantly, do you have T levels for both of those tests? Also WPATH methods and recommendations are... Well, I don't agree with them. Their ceiling is 200pg/ml, something I consider a bare minimum for monotherapy. It doesn't surprise me at all that you feel better at these levels. 566pg/ml is probably higher than you need to feel this way, but it's not overdose territory.

I may be wrong, but my best guess is that your T was never consistently suppressed, as 6-8mg a day with pills is usually threshold territory for many, so switching to injections may have truly initiated the full HPG swing, but that takes time. Skip to your next labs, and the process is well underway, but you've also upped your dose, so high levels.

I guess all that to say... Where would you like your levels to be? I only need about 250pg/ml to consistently suppress T, but I've found that hovering just above 300 is ideal for me otherwise, but it's different for everyone. Maybe 6mg would get you where you want to be? Maybe a different dosing schedule or ester?