Nandrolone vs testosterone: what the trials actually measured

The comparison arrives in the shop as a question and leaves as a shrug, because the published record does not contain it. The trial literature did not run that experiment. What it did run shows which measurement each study thought mattered, and where each one stops.

What “stronger” would even mean, and who measured it

The closest thing to a class-wide answer is an umbrella review of performance-enhancing drugs in healthy athletes, pooling 27 reviews and meta-analyses at level 4 of evidence. Its headline for the androgenic-anabolic steroid class is a 5% to 52% increase in strength and a 0.62 standard mean difference in lean body mass, followed by what the authors call subsequent lipid derangements.

The range is enormous, which is what a class containing compounds of very different potency looks like. And the paper does not break nandrolone out from testosterone, or any other member. The same review found no included studies at all on SARMs or ACE inhibitors, which is the same honesty problem those two categories have on their own.

So the strength figure on this page belongs to neither shelf. It cannot rank two products against each other.

The nandrolone trials: real, randomised, and never in healthy people

Four randomised trials exist. Each was built around a clinical problem rather than around an argument about anabolic potency.

The cleanest design is a 2×2 factorial trial in 79 patients on maintenance haemodialysis, of whom 68 completed twelve weeks. Participants got weekly nandrolone decanoate or placebo, double-blinded, alongside lower-limb resistance training during dialysis sessions three times a week or not. Lean body mass by DXA rose 3.1 kg with a standard deviation of 2.2 in the nandrolone arm. Quadriceps cross-sectional area went up additively in both the exercise and the nandrolone arms, at P = 0.01 and P below 0.0001. The authors close with the sentence that decides how much weight this carries: further studies are needed to determine whether these interventions improve survival.

A second trial, in 38 HIV-infected women with weight loss, ran nandrolone decanoate or placebo every other week for twelve blinded weeks followed by twelve open. Weight rose 4.6 kg, or 9.0%, and lean body mass 3.5 kg, or 8.6%, significant against baseline and against placebo in each case. Fat mass did not change significantly in either group. The safety read is the interesting sentence: no significant between-group differences in biochemical measures, in grade 3 or higher toxicities, or in reports of virilising effects, and the authors immediately add that a full assessment of safety cannot be made in a trial of this size.

The longest study is two years, in 65 osteoporotic women over 70, nandrolone or placebo every three weeks with everyone on calcium. Lumbar spine bone mineral density rose 3.4% at one year and 3.7% at two; femoral neck 4.1% and 4.7%; trochanter 4.8% at one year only. New vertebral fractures ran 21% against 43% on placebo. Lean body mass rose 6.2% at a year and 11.9% at two. Hemoglobin rose 14.3% against both baseline and placebo.

The fourth trial is the one that gets quoted least. A prospective randomised multicentric open-label study in 73 men with HIV-associated wasting, 69 completing twelve weeks. The treated arm gained fat-free mass 0.49 kg with a standard deviation of 1.26 and body weight 1.31 kg with a standard deviation of 1.87, both against baseline at p below 0.01. Now read the control arm: it also gained body weight, 0.99 kg with a standard deviation of 1.48, also significant. And the abstract prints no between-group fat-free-mass comparison at all.

That is what a small trial in a sick population looks like. It is honest to say the treated group improved. It is not honest to say it improved more than the control did, because that comparison is not in the paper.

What the testosterone side actually has

The testosterone evidence is larger, older, and confined to a narrower question: how much lean mass comes back, and how consistent is that.

A meta-analysis of controlled and randomised studies in men over 60 screened 2681 records, took 26 to full text, and included 11, three of which were then left out of the pooled analysis. Lean mass gain ranged from 1.65 kg to 6.20 kg across trials, with an effect estimate of 3.59 kg and a confidence interval of 2.38 to 4.81. The heterogeneity index was 98%: the trials disagree with each other almost completely. Fat mass fell on a pooled estimate of minus 1.78 kg, confidence interval minus 2.57 to minus 0.99, heterogeneity 81%.

The design that controls for exercise best is a head-down bed-rest study: healthy men aged 35 plus or minus 8, split into inactive control, exercise with placebo, and intermittent testosterone at 100 mg a week, two weeks on and two weeks off. Total, leg and trunk lean mass consistently decreased in the control, increased on testosterone, and changed little or not at all with exercise alone. Leg strength fell in the control and was protected in both active arms. Lean mass change correlated with strength change.

That is the closest thing here to a clean readout of what testosterone does to lean tissue under controlled conditions, in a model built to strip muscle out of healthy men rather than to build muscle up in a gym.

The prostate, where the evidence is thinnest and flagged

The one thing people ask about nandrolone that the above cannot touch is the prostate, and here the evidence tier drops to the bottom of the scale. There is a published case report: a patient with recurrent hormone-sensitive prostate cancer on salvage androgen deprivation therapy developed rapid progression after over-the-counter nandrolone injections. That is one patient. It proves a thing happened. It proves nothing about how often.

There is a rat study: 28 animals, 18 given nandrolone decanoate weekly for four weeks against 10 saline controls. Testicular weight fell, prostate and seminal vesicle weight rose, seminiferous tubule width narrowed, and the histology showed spermatid giant cells, vacuolation, degenerated spermatozoa, benign prostate hyperplasia and retained secretions. Lipid peroxidation products rose, which the authors read as oxidative damage.

Set side by side, a single case report and a four-week rat study are the entirety of the direct prostate evidence in this article. They are here because the signal is the reason people ask, not because the evidence is strong.

Where the catalogue sits

We carry both classes, and the honest version of the product page is thinner than the honest version of the question. Nandrolone decanoate and nandrolone phenylpropionate sit beside testosterone enanthate and cypionate, and the four randomised studies above are the entire clinical literature attached to the nandrolone shelf. For how claims in this category get tested and fail, what was never studied is the adjacent document.

What the data do not show

No trial in this set compares nandrolone against testosterone. Not one. The nandrolone evidence is four placebo-controlled trials in dialysis, HIV and osteoporosis; the testosterone evidence is pooled trials in men over 60 plus one bed-rest model. The strength and lean-mass figures belong to the steroid class as a whole, not to either molecule, and the class range of 5% to 52% is wide enough that a class average cannot rank two products.

No nandrolone trial here measured prostate volume, PSA, lipids, blood pressure or any cardiovascular endpoint. The prostate material is one case report and one rat study. No trial measured strength as an outcome in any of these populations, and none enrolled the healthy trained adults the question is actually asked from. The testosterone meta-analysis carries a heterogeneity index of 98%, meaning the studies behind the headline number do not agree with each other.

A body-composition change measured in dialysis patients, women with HIV, women with osteoporosis and bed-bound healthy men is not a promise about anybody’s physique. It is a record of what was measured, and the record stops there.

What we supply

The nandrolone and testosterone preparations above, as supplied by the manufacturer, tracked, from inside the EU. Batch documentation for every product that carries any is explained in the COA guide linked from the product page.

Research use only. This page summarises published trials for research reference. It is not medical advice, not a protocol, and not a suggestion for human use. Nothing we supply is for human or veterinary use.