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#4 in Weight Management

Force Factor LeanFire UC

by Force Factor

"GNC's best-selling thermogenic with Capsimax, green tea, and caffeine for metabolism and energy"

Amazon Rating
4.3/5
Reviews
8,000+
Price Range
$24-30
Servings
30 servings
GMP Certified
Our Editorial Rating
7.2
Good
FormCapsule
SubcategoryThermogenic Fat Burner
View on Amazon

Overview

Force Factor LeanFire UC is a thermogenic fat burner that combines Capsimax (concentrated capsaicin from cayenne pepper), green tea extract (EGCG), caffeine, and B vitamins for metabolism support and energy. Capsimax is a patented form of capsaicin that provides the thermogenic benefits of hot peppers without the stomach burn, thanks to its OmniBead beadlet technology. The formula also includes Advantra Z (bitter orange extract) and TeaCrine (theacrine) for sustained energy without the crash. Force Factor is one of GNC's best-selling brands and LeanFire has been a consistent top seller in the fat burner category.

Key Ingredients

IngredientAmount
Capsimax (Cayenne Pepper Extract)Included
Green Tea Extract (EGCG)Included
Caffeine~200 mg
Advantra Z (Bitter Orange)Included
TeaCrine (Theacrine)Included

Pros & Cons

What We Like

  • Patented Capsimax (no stomach burn)
  • TeaCrine for sustained energy
  • GNC best-seller
  • Multiple thermogenic pathways
  • 8,000+ Amazon reviews

What Could Be Better

  • Proprietary blend (doses undisclosed)
  • Contains bitter orange (controversial)
  • Stimulant-heavy formula
  • Weight loss effects are modest

Who Is This For?

Best For

  • Those wanting thermogenic metabolism boost
  • GNC shoppers
  • Energy + fat burning combo seekers
  • Those who tolerate stimulants well

Not Ideal For

  • Stimulant-sensitive individuals
  • Those with heart conditions
  • Those wanting transparent dosing
  • Pregnant or nursing women

Our Verdict

7.2/10 — Good

Force Factor LeanFire UC is a well-formulated thermogenic with patented Capsimax and sustained-energy TeaCrine. The proprietary blend is the main drawback — we'd prefer transparent dosing. For those who respond well to stimulant-based fat burners, it provides noticeable energy and thermogenesis.

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