Boldione, is an important industrial precursor for various steroid hormones. Boldione is a direct precursor (prohormone) to the anabolic steroid boldenone. It is advertised as a highly anabolic/androgenic compound promoting muscularity, enhancing strength and overall physical performance, and is available on the Internet and in health stores. Boldione was marketed as a prohormone "dietary supplement" for many years in the mid-2000's, but it is truly a potent precursor (ie. converts in the body) to the anabolic steroid Boldenone. In 2005 the Anabolic Steroid Control Act of 2005 classified boldenone as a Schedule III controlled illegal steroid.

Boldione:
https://drugs.ncats.io/drug/2166Q8568W

Boldione is a direct precursor to the anabolic steroid boldenone. Boldione is the oxidized form of boldenone, an this anabolic steroid is forbidden in EU countries in calves and bulls bred for meat production, and is illegally used as growth promoters, as they improve the growth and feed conversion in food producing animals. It is advertised as a highly anabolic/androgenic compound promoting muscularity, enhancing strength and overall physical performance.

Excerpt from hmdb.ca:
http://www.hmdb.ca/metabolites/HMDB0003422

Bodybuilding.com forums:
I took 600 mg/d of boldione for approx 5 weeks. Higher doses are just too expensive. As compared to 1-test or 1-AD I did not notice any strength increases until week 3 and they were very minor. No mass increases as compared to 1-AD during the first 3 weeks. 1 lb gain during week 4. I was not very impressed with boldione by itself and I still had libido suppression, but no feelings of lethargy. I also did not exp. that feeling as with 1-test of feeling strong, focused, and pumped.

After week 4, I added in 375 mg/d of SAUCE with the 600 mg/d of boldione. Strength and weight shot up significantly for the 12 days I was on both SAUCE and boldione. Gained approx 2-3 lbs in 12 days. Did not want to stop. Still had libido supp, but the feeling of lethargy common with 1-test was not there with both.

I would sum up by saying that even though boldione is touted as being good for mass by itself, I did not experience any significant results. However, it does seem to compliment the effects of 1-test if both are taken.

Excerpt from bodybuilding.com forums:
https://forum.bodybuilding.com/showthread.php?t=25804&page=1

2004 Bethesda swimmer Rachael Burke:
The U.S. Anti-Doping Agency, or USADA, will bar her from Olympic-related competitions for two years because of a positive test for a steroid.

She said she has spent months trying to determine what caused the positive test for a small amount of a little-known steroid called Boldione. Boldione, which is known as a steroid precursor because it metabolizes into an illegal steroid - boldenone - in the body.

Her claim of innocence is predictable. Drug testing catches dozens of athletes who, like Burke, say they did nothing wrong; most blame contaminated supplements or vitamin products, which are becoming a growing problem in sports. Three years ago, the International Olympic Committee commissioned a study that concluded that nearly 20 percent of supplements made in the United States showed some contamination.

Burke said she took every precaution to protect herself from the ignominy of a positive drug test, avoiding supplements so stringently that she refused to take even common vitamins. She said her family, coach and close friends believe her. But several officials connected to the drug industry or Olympic movement privately expressed skepticism at Burke's claims.

To the USADA, which oversees all Olympic drug testing in the United States adhering to the rules of the World Anti-Doping Code, the details of Burke's story are irrelevant. The USADA makes no attempt to determine whether athletes like Burke knowingly or innocently took steroids. It is enough to have found a positive test, anti-doping officials say.

World Anti-Doping Agency Chairman Dick Pound said there could be no leniency in such cases without destroying the system's credibility. Just because Burke didn't mean to cheat doesn't mean she didn't benefit from the drug, Pound said. And just because the drug was found in a tiny amount doesn't mean it wasn't there in a larger amount a few days before

USADA has all but gone on a crusade in recent years to inform athletes of the dangers of supplements, and Burke said she recalled receiving such warnings from USA Swimming as early as six years ago when she made her first national team. Virginia strongly urges its athletes to submit supplements to the university sports medical center for approval before taking them.

Excerpt from The Washington Post:
https://www.washingtonpost.com/archive/sports/2004/11/08/caught-cheating-or-was-she-cheated/bc0a39d9-f1fd-4d3e-9d11-32d3d6b18cb0/?utm_term=.68ef1eba2151

Boldione:

• An important industrial-scale precursor for a wide variety of steroid hormones
• Boldione is on the World Anti-Doping Agency's list of prohibited substances, and is therefore banned from use in most major sports.

In April 2008 the United States Drug Enforcement Administration published an "Initial Notice of Proposed Rulemaking" concerning the scheduling of three anabolic substances: boldione, desoxymethyltestosterone, and dienedione. In 2008, at the time of the proposal, these three substances were listed as ingredients in more than 58 dietary supplements which were available for purchase over the counter. Effective January 4, 2010 these three chemicals, including boldione, were classified as Schedule III Controlled Substances and became illegal in the United States.