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S-4 (Andarine), 25 mg

4.68 out of 5
(137 customer reviews)




S-4 (Andarine) Research Profile:


Description: 1st gen SARM; a tried-and-true anabolic; moderate metabolic enhancements; effects often cited as a dry, hard, lean, etc.

Known for: Increasing muscle mass and hardening appearance.

Commonly stacked with: Typical bulking stack: S-4, YK-11, MK-677 | optional: MK-2866

Side-effects: Testosterone suppression with prolonged use; temporary blurry or "yellow tint" vision in some users


S-4 (Andarine) Chemical Profile:

Clinical data

Selective Androgen Receptor Modulator
S4, S-4, Andarine, Andarin, Acetamidoxolutamide, Androxolutamide, GTx-007
By mouth
US: Investigational New Drug
GTX, Inc.

Pharmacokinetic data

4-6 hours


(2S)-3-(4-acetamido-phenoxy)-2-hydroxy-2-methyl-N- (4-nitro-3-trifluoromethyl-phenyl)-propionamide

Chemical and physical data

441.357 g/mol
FC(F)(F)c1cc(ccc1[N+]([O-])=O)NC (=O)[C@@](O)(COc2ccc(cc2)NC(=O)C)C
1S/C19H18F3N3O6/c1-11(26)23-12-3-6-14 (7-4-12)31-10-18(2,28)17(27)24-13-5-8-16(25(29)30) 15(9-13)19(20,21)22/h3-9,28H,10H2, 1-2H3,(H,23,26)(H,24,27)/t18-/m0/s1


* These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. Selective Androgen Receptor Modulators (SARMs) have not been approved in the US by the FDA for human consumption as dietary supplements. In accordance with US laws pertaining to the use of Investigational New Drugs (IND's) products labeled as SARMs on this website are sold for laboratory and clinical research purposes only, are intended solely for investigational use, and are to be used exclusively for purposes of a clinical trial that is the subject of an effective investigational new drug application; otherwise, you are not authorized to purchase our products. By using this site and/or purchasing our products, you certify you and/or your organization is/are qualified to possess, handle, and administer the products you purchase, that SARMTECH and its owners/agents are not liable for any unintended effects or outcomes, and that you are 21 years of age or older.


137 reviews for S-4 (Andarine), 25 mg

  1. 5 out of 5

    Nathan (verified owner)

    I absolutely love this SARM and my research subjects saw noticable results within a week. Delivery was quick as always.

  2. 5 out of 5

    Antonio (verified owner)


  3. 5 out of 5

    David P. (verified owner)

    Research subject is killing it in the GYM !

  4. 4 out of 5

    Patrick (verified owner)


  5. 5 out of 5

    Matt M. (verified owner)

    Subject starting to see results!!!

  6. 4 out of 5

    Aadel (verified owner)


  7. 5 out of 5

    Vince (verified owner)


  8. 5 out of 5

    Anonymous (verified owner)


  9. 5 out of 5

    Kevin S. (verified owner)

    Subject felt tighter and harder immediately.

  10. 5 out of 5

    Chris C. (verified owner)

    Subject definitely saw increased strength about the 4th week in. Overall muscle mass did increase slightly. Would buy again.

  11. 4 out of 5

    Shawn (verified owner)

    Subject reports it feels like its helping with strength and gains. Stack with mk 677 for sure. Subject going up in weight all the time.

  12. 5 out of 5

    Anonymous (verified owner)

    Amazing results

  13. 3 out of 5

    Jamie Kretchman (verified owner)


  14. 5 out of 5

    Anonymous (verified owner)

    Subject drying out nicely

  15. 4 out of 5

    Renan Scomazzon Orlandin (verified owner)


  16. 5 out of 5

    Jon (verified owner)


  17. 5 out of 5

    Anonymous (verified owner)

    Great product and unbeatable price!

  18. 5 out of 5

    Aaron G. (verified owner)

    Subject’s strength increase has been noticeable in the past few weeks, breaking through plateaus pretty regularly and able to push harder.

  19. 5 out of 5

    Sean Devine (verified owner)

    Subject has been on long enough to notice a significant vascular change especially in the arms and neck. It’s great. The vision sides that come with s4 are annoying but at least you know they’re legit and subject has them. Good product.

  20. 5 out of 5

    Anonymous (verified owner)


  21. 5 out of 5

    Ariel (verified owner)

    Amazing products!

  22. 5 out of 5

    Charles O. (verified owner)


  23. 5 out of 5

    Chavdar (verified owner)

    Subject has been taking for few weeks and I’ve observed gains of strength and ability to work out longer than usual.

  24. 5 out of 5

    Fabiano Purper (verified owner)


  25. 5 out of 5

    Richard Hernandez (verified owner)


  26. 5 out of 5

    ms931878 (verified owner)

    Noticed an increase in subject’s vascularity and strength

  27. 5 out of 5

    Alexander A. (verified owner)

    Great product, arrived quickly! Dried out very quickly, lots of vascularity and tighter skin.

  28. 5 out of 5

    Mike C. (verified owner)

    Great gains and recovery.

  29. 5 out of 5

    Marvin (verified owner)

    Subject seeing great results, muscles are getting harder and stronger!

  30. 3 out of 5

    scott (verified owner)


  31. 5 out of 5

    Anonymous (verified owner)


  32. 5 out of 5

    Anonymous (verified owner)


  33. 5 out of 5

    Mario (verified owner)

    Price per mg can’t be beat! Fast shipping too! Now for the product itself, first time trying out s4 and I’m loving what I’m seeing. Loss of some bf and some muscle hardness. Seeing some new cuts too. I’m sure this stacked with Ostarine and some Cardarine would make some more pronounced results.

  34. 5 out of 5

    Arjun Mohan (verified owner)

    Genuine product, S4 works best in my experiments.

  35. 4 out of 5

    Ryan M. (verified owner)

    Happy with the S-4 so far, been stacking it with rad-140 for about 3-4 weeks! Noticing subject’s muscles starting to get that rock hard feeling.

  36. 4 out of 5

    Kristopher Morrow (verified owner)

    It will give your test subject yellow tint to eye sight. Just go 5 on 2 off.

  37. 5 out of 5

    Austin F. (verified owner)

    Been testing this product for only 3 weeks, halfway through the first cycle with this product. Subject notices considerable gains in vascularity, veins popping out in places never before seen. No noticable weight loss so far, but I have noticed a considerable gain in muscle possibly partly due to sarmtech LGD, besides that I have noticed a V shaped taper developing to the body. Excited to finish out the rest of the cycle. Sarmtech as a company has so far been perfect in every way, I wouldn’t trust my sarm needs to anyone but them!

  38. 5 out of 5

    Anonymous (verified owner)

    Great for cutting up !! 12 week cycle results in lean muscle mass..

  39. 4 out of 5

    Allen (verified owner)

    Subject had a fairly good response to S-4. The subject feels it is a good SARM, but appears to require a heavier dosage than others for a similar response. There was a slight increase in vascularity. Stacking with Cardarine has produced good results in holding muscle and decreasing body fat. -2.5% fat while holding steady at 35-36% muscle. Alone, S-4 might be more effective at a higher dosage than currently administered to the subject, 1 AM, 1 PM.
    Service & shipping from SARMTECH was on point. Requested items arrived very quick, and backorder status was communicated and filled/shipped as notified. Very satisfied with product, SARMTECH gets 5 stars.

  40. 5 out of 5

    Anonymous (verified owner)

    Great cutter

  41. 5 out of 5

    alan cucchiella (verified owner)

    Reasonably priced nice quality and quantity

  42. 5 out of 5

    Abisai Aguilar (verified owner)

    Amazing sarm, subject lost 5lbs of fat and I really like s4

  43. 5 out of 5

    Brian W. (verified owner)

    Fast awesome shipping, Great gains, Great price. Stacked rad140 (15mg), mk677 (15mg), LGD4033 (10mg) and MK2866 (15mg) and very pleased with experiment results so far! Only 2 weeks in and subject is breaking major records. Will start S4 in week 5 @ (25mg twice daily) and up rad140 dose to (30mg). Will definitely do a PCT along with GW501516.

  44. 5 out of 5

    william (verified owner)

    I am actually super impressed by this s4 AND by sarmtech! I usually experiment with lgd, but lately with rad140, but igot s4 since the others were out. I didnt think it’d work as well being 1st generation Sarm! Vascularity, pumps, hardness ….. all way up after 4 weeks

  45. 5 out of 5

    Mjjc5291 (verified owner)

    Test subject showed increase in lean muscle mass along with decrease in fat. Very dry hard look in terms of physique with minimal suppression to test subjects test. Pct was still administered

  46. 5 out of 5

    Anonymous (verified owner)

    Definitely worked great on my test subject! Fast Shipping!

  47. 5 out of 5

    Rich (verified owner)

    I’ve been stacking cardarine and andarine for 3 or so years in my studies. 1st time using sarmtech and not disappointed. Good pricing too and shipping across the pond was reasonable $ and about a week.

  48. 4 out of 5

    Shell (verified owner)

    Subject has been using it for a cutting cycle. About 2 weeks so far, and working well. Seems less effective short term as GW which I used in my past experiments.

  49. 5 out of 5

    Tina (verified owner)

    Surprisingly pleased with this product (my second purchase). Great results, and a great price 🙂

  50. 5 out of 5

    Katie T (verified owner)

    Stacking with 501516 for weight loss experiment. I”m really really pleased with results so far. Starting 161 lb @ 5’4″. Charting for 8 weeks and at the halfway point. Scale today: 149, so down 12 lbs in 4 wks! Subject also still running on treadmill 45min 3x wk. Also subject is eating clean, low carbs, high protein, etc, but not starving by any means!

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S-4 Andarine SARM Capsules
S-4 (Andarine), 25 mg