6-OXO or androstenetrione is a “natural estrogen blocker” created by Egopharm. It is sold as a dietary supplement in the bodybuilding industry. Itlower estrogen levels in the body and increase testosterone. Wondering how 6-OXO works, what are its pros and cons and if it is really effective as it claims to be? Here’s a review to help you out.

What is 6-OXO?

6-OXO is a steroidal aromatase inhibitor known as suicidal inhibitor as it irreversibly binds to the aromatase enzyme (an enzyme that aromatizes androgens and creates estrogen). Once aromatase is inhibited, it follows that estrogen is minimized leading to a boost in testosterone.

The ingredient 6-OXO is increasingly more difficult to find and buy due to its strength. Also, 6-OXO must never be used post cycle therapy as it is still considered a steroid. Its steroidal effects can most probably impede with recovery of natural testosterone production.

An 8 week study was conducted at Baylor University to identify the effects of 300 mg or 600 mg of 6-OXO used by resistance trained men. The study displayed a boost of 90% for 300 mg group and 84% for the 600 mg group. The study determined that the ratio of free testosterone to estradiol increased considerably.

6-OXO Chemical Structure


  • Chemical Name: 4-androsten-3,6,17-trione3,6,17-androstenetrione androst-4-ene-3,6,17-trione 6-ketoandrostenedione
  • Chemical Formula: C19H24O3
  • Molecular Weight: 300
  • CAS: NA
  • Q Qatio: NA
  • Anabolic #: NA
  • Androgenic #: NA
  • Oral Bioavailability: Estimated at 40%
  • AR Binding Affinity: NA
  • SHBG Binding Affinity: NA
  • Half Life: 3-6 hours

The ingredient 3, 6, 17-androstenetrione is usually used in testosterone builders and estrogen blockers but have no weight loss or fat loss effects. 4-Androstene-3, 6, 17-trione is a lasting estrogen blocker that can be gauged during urine testing. When estrogen is obstructed, luteinizing hormone (LH) is released and testosterone production takes place.

Benefits of 6-OXO

  • Stops estrogen production
  • Increases testosterone levels

Right Dosing

The suggested dosage for 6-OXO is 300-600 mg per day for 8 weeks. Studies show that running 6-OXO for 8 weeks is safe and no adverse side effects will be experienced.

FYI: 6-OXO should NOT be taken by women.

The Top Supplement Containg 6-OXO

E-Control RX

E-Control RX by IronMag Labs is a prohormone that helps decrease water retention and once you’ve finished your cycle. 

Possible Side Effects of 6-OXO

  • Low estrogen levels – can lead to serious side effects in men (e.g. fatigue, joint pain, memory lapses, rise in cholesterol levels, night sweats and decreased libido)
  • Hair Loss – increased DHT can lead to alopecia
  • Risk of BPH (benign prostatic hyperplasia) – excess DHT can bind to the prostate causing it to swell
  • Acne – an increase in testosterone, DHT or changing hormonal levels can lead to acne (especially in the shoulders and back)
  • Does not totally impede estrogen

Note: These side effects are based on a prolonged use of 6-OXO (more than 8 weeks).

6-OXO Testimonials

For the most part, users of 6-OXO did observe an increase in testosterone and got some good gains from it.

One user said: 

“…Nice strength gains, seemed to lean out nicely while actually increasing in strength, a feat in itself if anyone has ever contest dieted!...” 

But, some of the users also reported they’ve experienced acne, drowsiness and aggression every now and then.

Final Review

6-OXO is one of the rare supplement ingredients that truly worked as promised. Men taking the 6-OXO supplement had seen a boost in testosterone. You might experience steroid-like side effects so preparing yourself, knowing what the probable side effects are and starting at the lowest possible dosage can help you make the most of what 6-OXO has to offer!