Two questions decide everything. Whether the tissue is gland or fat, and how long it has been there. The first determines whether any medication could ever help, the second determines whether it still can. Most men get told to diet at gland, or to take something for fat.
Lie down, put your hand behind your head, and feel the area under the nipple with the flat of your fingers from the outside in. You are looking for whether something firm exists that is different from the surrounding tissue.
The assessment weighs texture, location, tenderness, asymmetry and a distinct edge against whether the tissue changes with body fat, since the two conditions look similar in a mirror but need opposite answers. Dieting does nothing for established gland, and a SERM does nothing for fat, which is why so many men spend years pursuing the wrong one. If your body fat itself is the open question, cross-check it against the FFMI Calculator.
Tissue moves from a florid, actively proliferating phase in the first six months, through a transitional window where response to medical therapy is falling off, into a fibrous phase beyond about twelve months where hormonal treatment has little left to act on. The tool places you on that timeline and is explicit about which phase you are in, because the honest answer past a year is usually surgical rather than another supplement.
SERMs and aromatase inhibitors are not interchangeable here, and the trial evidence for each is kept separate rather than blended into one vague recommendation. The tool also flags when a progestagenic compound such as nandrolone or trenbolone is the likely driver, since that changes which mechanism actually needs addressing. Cross-check your compound history against the Estrogen / AI Dose Calculator if estradiol is part of the picture, and confirm your labs against the Bloodwork Analyzer.
Glandular tissue is a firm, rubbery, discrete disc concentric under the nipple, often tender, with a distinct edge, and it does not shrink when you diet. Pseudogynecomastia is soft and diffuse across the whole chest with no palpable disc, and it does resolve with fat loss. The single most useful test is whether it changes when you lean out, which the tool asks directly.
Because tissue histology shifts over time. Under about six months it is in a florid phase of active ductal proliferation with loose vascular stroma, which is when medical therapy has something to work on. Beyond about twelve months it has typically become fibrous, hyalinised stroma, and medical therapy has little effect on it at that point. That clock, not the size of the tissue, is what determines whether a drug has a realistic chance.
The evidence says largely not. In a randomised trial, gynecomastia developed in 73% of men on placebo, 10% on tamoxifen, and 51% on anastrozole, meaning the aromatase inhibitor did not significantly reduce incidence. A separate placebo-controlled trial in pubertal gynecomastia found no significant difference between anastrozole and placebo. Tamoxifen, by contrast, produces some reduction in roughly 74 to 95% of cases when used early. Reviews generally conclude aromatase inhibitors lack adequate evidence for established gynecomastia.
Because those compounds drive breast tissue substantially through progesterone-receptor activity rather than aromatisation alone. An aromatase inhibitor only addresses the aromatisation pathway, so on a 19-nor compound it is often aimed at the wrong mechanism entirely, which is the usual reason people conclude their AI dose was too low when the real issue is the target.
Once tissue is hyalinised fibrous stroma, no medication dissolves it, and that is a property of the tissue rather than a failure of any particular drug or dose. Subcutaneous mastectomy is the only approach that reliably removes it, is a routine day procedure, and Grade I presentations in particular have excellent results. Knowing this early avoids years spent on supplements and protocols with nothing left to act on.
