Letro igf1 study

n both dosage groups a statistically significant increase in the IGF-I levels was observed during three months of letrozole treatment

Serum insulin-like growth factor (IGF)-I and IGF-binding protein-3 levels were measured in two groups of postmenopausal women with advanced breast cancer, who received the aromatase inhibitor letrozole 0.5 or 2.5 mg p.o. once daily. Blood samples were obtained from 15 patients in each dose group at baseline, and one and three months after starting therapy. Circulating IGF-I and IGFBP-3 concentrations were determined by means of radioimmunoassay. In both dosage groups a statistically significant increase in the IGF-I levels was observed during three months of letrozole treatment (P=0.003). In addition, the multiple testing procedure yielded in the whole patient population a significant result in the comparison between mean IGF-I values after three months of therapy and those observed at baseline (P=0.004), the estimated average increase being of 24%. No significant result was obtained in the analysis for the dose effect (P=0.077) and for the time x dose interaction (P=0.208). Circulating IGFBP-3 levels did not appear to be affected by letrozole treatment in either of the dose groups. This is the first report concerning the short-term effects of letrozole on components of the IGF system in breast cancer patients; further investigations are warranted in order to confirm these preliminary data.

instead of taking IGF or hgh + slin lets start using Letro at high dosage and grow!!! of course even if Letro increase IGF we cant use him for that because you will crash estrogen , fell like shit , no sex drive, easy to get one injury and many other side effects.

MTS-Head Coach wrote:instead of taking IGF or hgh + slin lets start using Letro at high dosage and grow!!! of course even if Letro increase IGF we cant use him for that because you will crash estrogen , fell like shit , no sex drive, easy to get one injury and many other side effects.

Yes true brother also nolva can cause blood clotting strokes also risky

Both tamoxifen and raloxifene increase your risk of developing blood clots in a vein in your leg (deep venous thrombosis) or in your lungs (pulmonary embolism). These clots can sometimes cause serious problems, and even death.

I do think now though letro safer if we still keep estro higher thoughts ?

DarrenW29 wrote:Yes true brother also nolva can cause blood clotting strokes also risky

Both tamoxifen and raloxifene increase your risk of developing blood clots in a vein in your leg (deep venous thrombosis) or in your lungs (pulmonary embolism). These clots can sometimes cause serious problems, and even death.

I do think now though letro safer if we still keep estro higher thoughts ?

here is the reason more bodybuilders are dying today: Almost all top coaches use tamoxifen every day off season and pre contest . Yes this days they look hard even offseason because estrogen always controled , Can be one of the reason of more health problems today . because using tamox all year is not good for sure.

MTS-Head Coach wrote:here is the reason more bodybuilders are dying today: Almost all top coaches use tamoxifen every day off season and pre contest . Yes this days they look hard even offseason because estrogen always controled , Can be one of the reason of more health problems today . because using tamox all year is not good for sure.

Definitely coach and lower igf1 as you know igf1 high off-season as much as possible is key off-season no worry on estrogen unless needed but we need it

The E2 to IGF-1 relationship is one of the most underappreciated aspects of managing a cycle. Crashing oestrogen does not just kill mood and libido - it actively limits anabolic signaling through multiple pathways. That is the core problem with overly aggressive AI protocols. I aim to keep E2 in the high normal range for this reason and my bloodwork over time supports this approach.

The E2 to IGF-1 relationship is mechanistically established. Aromatase converts androgens to E2 which signals IGF-1 production via JAK-STAT pathway. This is precisely why crashing oestrogen with aggressive AI protocols not only feels terrible but actively reduces an anabolic signal. My protocol keeps E2 at 30 to 40 pg per mL which I have found optimal through systematic testing over 4 years of consistent bloodwork.

This study illustrates an important principle: oestradiol is an anabolic hormone with direct effects beyond its secondary role in cycles. E2 stimulates IGF-1 production via oestrogen receptor-alpha in the liver, upregulates GH receptor sensitivity, and has direct anabolic effects on muscle tissue. The traditional view that E2 is purely a side effect to be minimised misses this entirely. Optimal E2 for anabolic purposes appears to be in the range of 35 to 50 pg per mL for most men on cycle.