60 Servings | Organic Mushroom Blend
"Stack this with my pre-workout daily - endurance has noticeably improved and recovery feels faster between sessions."
Enhanced Endurance & Stamina
PeakO2® clinically shown to improve oxygen utilisation (VO2 max) to help you train harder for longer.
Increased Power Output
Supports sustained strength and performance during high-intensity exercise.
60 Servings / 120g
Included
Flavour: Unflavoured
Order within --h --m
for Next Day Delivery
£19.99
EFECTIV® Peak O2®
PeakO2® is an organic-certified combination of six adaptogenic mushrooms including Cordyceps, Reishi, King Trumpet, Shiitake, Lion's Mane and more.
PeakO2® is used by athletes to support VO2 max, power output, and sustained endurance performance during high-intensity training.
VO2 Max
Power Output
Faster Recovery
Adaptogenic
Calories
8kcal
Protein
0.3g
Carbs
1.4g
Fat
0.1g
Detailed Breakdown
| Nutrient | 1 Scoop (2g) |
|---|---|
| of which Saturates | 0.0g |
| of which Sugars | 0.1g |
| Fibre | 0.2g |
| Salt | 0.0g |
| PeakO2® Mushroom Blend | 2000mg |
Ingredients
PeakO2® Organic Mushroom Blend [Cordyceps militaris (Cordyceps), Ganoderma lucidum (Reishi), Pleurotus eryngii (King Trumpet), Lentinula edodes (Shiitake), Hericium erinaceus (Lion's Mane), Trametes versicolor (Turkey Tail)] (2000mg). No fillers or unnecessary additives.
!
Allergen Advice
Contains no major allergens. Manufactured in a facility that handles Milk, Soy, Wheat, Eggs, Peanuts, Tree Nuts, Fish and Shellfish.
✓
Artificial Additives✓
Proprietary Blends✓
Banned Substances1
Scoop
Add 1 level scoop (2g) to your shaker or glass.
2
Mix
Add 200–300ml of cold water, juice, or your pre/intra/post-workout shake.
3
Stack
Can also be stirred into a smoothie or morning coffee for daily use.
Water
Clean & Unflavoured
Shake
Stack with pre or post-workout
Coffee
Add to morning routine
Recommended Timing
Pro Tip
For best results, use PeakO2® daily — consistent use builds adaptogenic benefits over time.
Standard Delivery
2-3 Working Days - £1.99
Free over £20Express Delivery
Next Working Day
£2.9930-Day Money Back Guarantee
Train with confidence. If you don't feel the difference, return the unused portion for a full refund.
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EFECTIV® PeakO2® Organic Mushroom Blend | 60 Servings | VO2 Max
60 Servings / 120g / Unflavoured
£19.99
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The Science
What has PEAKO2® research actually studied?
PEAKO2® has been examined in small, randomised human trials measuring outcomes such as maximal oxygen uptake, time to exhaustion and cycling power.
Aerobic Performance
Studied for potential effects on VO₂ max and time to fatigue
Power Output
Examined in high-intensity cycling performance trials
Exercise Response
Researched for its effects on blood lactate and exercise tolerance
"Made by athletes and beneficial for anyone, PeakO2® makes a big impact where it matters the most: performance."
Compound Solutions, developers of PEAKO2®
The Efectiv Difference, How We Compare
Why athletes choose us over the competition.
EFECTIV
Standard Mushroom Powder
Mushroom Blend
PeakO2® Certified
Generic Extract
Organic Certified
Fillers & Additives
Clinically Studied
Servings Per Pack
60
30
Price Per Serving
£0.33
£0.60+
World Class Performance
Trusted by Champions.
25+ Efectiv Athletes
+30
Elite CrossFit
Harry Lightfoot
UKs #1 CrossFit Athlete
HYROX PRO
Sophie Thornton
High performance HYROX Pro athlete
IFBB Pro bodybuilder
Abou Konate
Open Bodybuilding Pro aiming for the Olympia
Elite CrossFit
Joe Hurley
Elite Crossfit Athlete
crossfit•hyrox•bodybuilding•crossfit•hyrox•bodybuilding•
Transparent Label
Inside the Scoop.
We don't hide behind proprietary blends. Every ingredient is listed with its exact dosage so you know exactly what you're fueling your body with.
2000mg
PeakO2® Blend
Patented Mushroom Complex
Six organic adaptogenic mushrooms clinically shown to improve VO2 max, increase peak power output, and reduce time to exhaustion.
—
Cordyceps militaris
Adaptogen
The star of the blend — Cordyceps is clinically studied for its ability to increase oxygen delivery to muscles, directly improving aerobic capacity and stamina.
—
Lion's Mane
Cognitive Adaptogen
Supports mental clarity and focus during training, helping you stay sharp and driven through tough sessions.
Lab Verified
Quality You Can Check
We believe in clear, verifiable standards. View the product certificate below for details of the checks completed, the results reported and the formula tested.
Open CertificateProduct
EFECTIV® PeakO2® Organic Mushroom Blend | 60 Servings | VO2 Max
Status
PASS
Formula Transparency
Full Dosages Listed
Documentation
Available
UK Manufacturing
Always
Real Results. Real People.
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Frequently Asked Questions
PeakO2® is a patented blend of six organic adaptogenic mushrooms clinically studied to improve oxygen utilisation (VO2 max), increase peak power output, and reduce time to exhaustion. It helps your body adapt to physical stress so you can train harder and recover faster.
PeakO2® is flexible — take it pre-workout for performance, intra or post-workout for recovery, or add it to your morning coffee as part of a daily adaptogen routine. Consistent daily use delivers the best results.
The flavour is very mild and earthy - it blends easily into shakes, water, or coffee without overpowering the taste. Most users don't notice it when mixed into a pre-workout or protein shake.