Dexterz Labs Andarine S4 25mg 90 Capsules

Andarine, coded S-4 and also written GTx-007, is one of the earliest non steroidal selective androgen receptor modulators to be characterised in detail, developed at the University of Tennessee and by GTx. This bottle contains 90 capsules at 25mg of andarine per capsule, made in the United Kingdom. Supplied strictly as laboratory research material and not for human consumption.

Product specification

What the research says about andarine

Andarine is a foundational compound in the SARM literature. Gao, Dalton and colleagues, publishing in Endocrinology in 2005, reported that S-4 restored levator ani muscle mass and bone strength in castrated rats to intact levels while producing only partial stimulation of the prostate, which demonstrated tissue selectivity in a way that had not been shown clearly before. Kearbey and colleagues followed in Pharmaceutical Research in 2007, reporting that S-4 prevented bone loss and preserved bone mineral density in ovariectomised rats, a model used for postmenopausal osteoporosis.

Those two lines of work, muscle and bone in rodent models, are the substance of the andarine evidence base. The compound was not carried into late stage human trials, and there is no published phase II or phase III efficacy study in people. Pharmacokinetic work describes a short half life of roughly four to six hours, which is why study protocols in the literature used divided daily administration rather than the once daily schedule seen with LGD-4033 or MK-677.

The effect that distinguishes andarine in the anecdotal record, transient visual disturbance and a yellow tint to vision, is not described in the rodent papers and has not been the subject of a controlled trial. The proposed explanation is an interaction with retinal photoreceptor function, and the reports describe it as reversible on stopping, but it should be treated as an unverified observation rather than an established pharmacological finding.

Quality and testing

Dexterz Labs products are manufactured in the UK to a fixed strength per capsule with the batch number printed on every bottle. Independent batch certificates of analysis, confirming identity by HPLC or LC-MS and stating purity, are being commissioned and will be published on this page as each batch is tested. Until then, if you need the batch report for research records, contact sales@sarmsstore.co.uk with your batch number.

Frequently asked questions

Is andarine legal in the UK in 2026? SARMs are not controlled substances under the Misuse of Drugs Act 1971, so buying and possessing andarine as a research chemical is lawful in the United Kingdom in 2026. What is not lawful is selling or advertising it for human use, because the MHRA treats it as an unlicensed medicine in that context. That is why this listing, and every listing on this site, is worded for laboratory research and nothing else.

How fast is delivery? Orders placed before the daily cut off are despatched the same working day on a tracked UK next day service. Everything leaves in plain outer packaging with no reference to the contents or to the compound on the outside of the parcel. We ship worldwide, although some destinations are restricted because of local customs rules, and restricted countries are listed at checkout.

How should the capsules be stored? Store sealed, below 25C, in a dry place away from sunlight and heat. Under those conditions the material is stable to the expiry date shown on the bottle. Humidity is the usual problem with capsules, so a cupboard is better than a windowsill or a bathroom shelf.

Is andarine banned in sport? Yes. Andarine is prohibited at all times under section S1.2 of the WADA prohibited list. It was among the first SARMs for which anti doping laboratories validated a detection method, and it appears regularly in adverse analytical findings, frequently traced to contaminated supplements.

How does andarine differ from ostarine? Both came out of the same research programme and both are non steroidal androgen receptor ligands, but ostarine progressed into phase II and phase III human trials while andarine stopped at preclinical work. Andarine also has a much shorter half life and is supplied at a higher milligram strength for that reason. The reported visual effect has no analogue in the ostarine literature.

Research use only. This product is supplied strictly for laboratory and research purposes and is not for human consumption. It is not a medicine, it is not a food supplement, and it is not intended to diagnose, treat, cure or prevent any disease. Sold to persons aged 18 or over only.