How USADA / Anti-Doping Testing Works in MMA

The history

From July 2015 to December 2023, the UFC's anti-doping program was administered by USADA (United States Anti-Doping Agency). USADA is an independent non-governmental agency that also runs Olympic-sport anti-doping in the United States.

The USADA program was the most-rigorous anti-doping system in combat sports. It included:

• Random year-round out-of-competition testing
• In-competition testing on fight night
• A whereabouts requirement (fighters had to provide a 1-hour daily window of availability)
• A 6-month testing pool exit requirement (a fighter who left the UFC had to remain testable for 6 months before being eligible to return)

In December 2023, the UFC terminated the USADA contract and transitioned to Drug Free Sport International (DFSI) as the testing partner. The transition was driven by:

• USADA's public criticism of the UFC's decision to allow Conor McGregor to return without serving the full 6-month testing pool exit
• Cost considerations
• The UFC's preference for a less-stringent testing partner

The DFSI program is less-rigorous than the USADA program; the change has been criticized by anti-doping advocates as a downgrade.

The substances tested

The list of banned substances follows the WADA (World Anti-Doping Agency) Prohibited List, with UFC-specific adjustments. The main categories:

• Anabolic agents (testosterone, anabolic steroids, SARMs)
• Peptide hormones and growth factors (HGH, EPO, IGF-1)
• Beta-2 agonists (clenbuterol)
• Hormone and metabolic modulators (aromatase inhibitors, SERMs)
• Diuretics and masking agents (furosemide, hydrochlorothiazide)
• Stimulants in competition only (amphetamines, cocaine, methylphenidate)
• Cannabinoids in competition only (THC; CBD is permitted)
• Glucocorticoids in competition only (oral, intravenous, intramuscular, or rectal administration)
• Beta-blockers in shooting only (not applicable to MMA)

The full list is updated annually and matches the WADA Prohibited List with UFC-specific exemptions (e.g., the 2023 change to permit CBD).

How testing works

The standard USADA / DFSI testing protocol:

1. Notification: a doping control officer (DCO) arrives at the fighter's location (gym, home, hotel) with no advance notice
2. Witnessing: the fighter is observed at all times until the sample is collected
3. Collection: the fighter provides a urine sample under direct observation (the DCO watches the urine flow into the cup)
4. Sealing: the sample is split into two bottles (A sample and B sample), sealed, and transported to the lab
5. Lab analysis: the A sample is tested first; if positive, the fighter is notified
6. B sample: the fighter can request the B sample be tested as a confirmation; if the B sample is also positive, the result is final

Blood samples are also collected for certain tests (HGH testing requires blood). The collection protocol for blood is similar to urine but with phlebotomist-trained DCOs.

The Athlete Biological Passport

USADA / DFSI maintains an Athlete Biological Passport (ABP) for each fighter — a longitudinal record of biomarker values over time. The ABP allows detection of doping without a positive test if the biomarker pattern (testosterone:epitestosterone ratio, hematocrit, etc.) shifts in ways that suggest doping.

The ABP is the modern frontier of anti-doping; many high-profile cases (e.g., Lance Armstrong's downfall) involved biological passport evidence rather than positive tests.

The most-cited UFC test failures

Jon Jones (multiple)

• 2016: estrogen blocker (Clomid + Letrozole) — 1-year suspension after the original 4-year was reduced
• 2017: turinabol metabolite — 15-month suspension after the original 4-year was reduced
• 2019: picogram-level turinabol metabolite — no suspension; classified as a "pulsing" of the previous metabolite

Jones's history is the most-cited test-failure record in UFC. The "pulsing" defense (residual turinabol metabolite from the previous positive) is contested by anti-doping advocates.

Anderson Silva

• UFC 183 (January 2015): drostanolone and androsterone; the result of his fight with Nick Diaz was changed to a No Contest
• 2017: testosterone modulators flagged in commission-level testing

Brock Lesnar

• UFC 200 (July 2016): clomiphene (an estrogen blocker); the result was changed to a No Contest and Lesnar was suspended

Yoel Romero

• 2016: ibutamoren (a growth hormone secretagogue); reduced to a 6-month suspension after the source was identified as a contaminated supplement

Conor McGregor

• 2023-2024: extended testing pool exit (~22 months) without serving the full window before the 2024 return; the controversy contributed to the USADA termination

Sean O'Malley

• 2019: ostarine (a SARM); 6-month suspension after the source was identified as a contaminated supplement

The "contaminated supplement" defense

A significant percentage of UFC test failures involve fighters claiming a contaminated supplement caused the positive test. The USADA review process for contaminated-supplement claims:

1. The fighter provides the suspected supplement product (or the lot number)
2. The supplement is independently tested by a USADA-approved lab
3. If the supplement is found to contain the banned substance, the fighter's suspension is reduced
4. The supplement is added to USADA's Supplement 411 high-risk list

The defense is widely contested. Many anti-doping advocates argue the contaminated-supplement system is a loophole that allows knowing dopers to evade full suspension by claiming contamination.

How fighters avoid violations

The legitimate paths for fighters to avoid violations:

• Use only USADA-approved supplements: the Supplement 411 program lists supplements that have been independently tested and confirmed safe
• Report all medications to the UFC: any prescription medication should be cleared with the UFC medical team before use
• Provide whereabouts information accurately: the daily 1-hour window must be kept up to date
• Use therapeutic-use exemptions (TUEs) for permitted reasons: a fighter with a documented medical need for a banned substance can apply for a TUE; the application is reviewed by an independent medical panel

The DFSI transition impact

Since the December 2023 transition to DFSI:

• The testing frequency has reportedly decreased
• The whereabouts requirement remains but enforcement has been less strict
• The 6-month re-entry pool requirement has been adjusted to allow shorter waits for certain returning fighters
• The Supplement 411 program is no longer the UFC's official supplement reference

The full impact of the DFSI transition is still being analyzed by the anti-doping community as of 2026.

Conclusion

The UFC's anti-doping program is the most-developed in combat sports but is in a state of flux after the USADA-to-DFSI transition. The system catches many positive tests but is criticized for the contaminated-supplement defense, the inconsistent enforcement of the testing pool, and the reduced rigor under DFSI. For fans, understanding the program is essential context for evaluating fighter performances — the question of "is this fighter clean?" is unavoidable in modern MMA.