PeakO2 boosts athletic performance by providing a strong mushroom mix that supports endurance, delays fatigue, and speeds recovery. PeakO2 is a patented blend of six organic certified mushrooms, including cordyceps and lion's mane, designed to support energy production and resilience under strenuous training. Efectiv Nutrition is a UK based brand known for transparency and quality, using branded ingredients from trusted suppliers.

Available Sizes & Variants:

120g PeakO2 powder — unflavoured and easy to mix with drinks or shakes.

Benefits & Features:

• Endurance is supported during training as PeakO2 helps delay fatigue and sustain power.
• The key active ingredient PeakO2 is a patented blend of six organic certified mushrooms, designed to support energy production and resilience under strenuous training.
• Unflavoured powder blends easily with other supplements.
• Daily use aligns with clinically studied dosing, supporting measurable performance benefits when taken consistently.
• Brand quality and transparency are central, with PeakO2 supplied from trusted partners in the USA and disclosed ingredient details, plus rigorous sourcing and manufacturing checks that assure purity and consistency.

PeakO2's six mushroom blend is produced in the USA under certified organic conditions, using branded ingredients to ensure consistency from batch to batch. Made in the USA. Branded ingredients matter. In trials with athletes, daily doses of 2–4g for about three weeks delivered improved peak power and longer time to exhaustion, while maintaining a clean, stimulant-free profile. The formula's adaptogenic mix also brings antioxidant beta-glucans, supporting recovery and immune resilience. This product sits alongside a broad sports nutrition landscape that includes creatine, probiotics, and vitamin d supplement to help athletes build resilience and performance.

Cordyceps militaris (Cordyceps), Ganoderma lucidum(Reishi), Pleurotus eryngii (King Trumpet), Lentinulaedodes (Shiitake), Hericium erinaceus (Lion s Mane),Trametes versicolor (Turkey Tail) (as PeakO2 )

• GTIN: 5060347312759
• Manufacturer: Efectiv Nutrition
• Categories: Bodybuilding SupplementsEfectiv NutritionNew ArrivalsNew In Supplements & Vitamins
• Best buy: 6 - 24 months+

United Kingdom Shipping:

Orders placed by 2pm (Monday to Friday) are dispatched the same day. Orders placed after 2pm will be dispatched the next working day.

Free shipping on orders over £50 to the UK.

Returns: Our products are meant to make you feel healthy and at your best. If you need to return your item, you can do so free of charge within 30 days in the same original and unopened packaging. Subject to T&C's.

Please consult the product packaging for accurate instructions on how to use the product.

The Primary Benefit Is: Exercise Performance Support

Exercise performance support explains how the product helps your body cope with physical stress and keep you moving during training and competition. The PeakO2 mushroom blend is the main ingredient, offered as a simple, organic-certified mix with no extra additives.

This blend is meant to slot into your training routine to boost endurance during tough efforts and recovery stretches, with a focus on sticking to a daily habit to maximise benefits.

How Does This Support Exercise Performance?

The PeakO2 mushroom blend could help lift endurance and peak power, and it can push fatigue back during intense workouts. It is aimed at supporting oxygen utilisation and cellular energy production, which line up with claimed ergogenic effects of the blend.

Plus, the blend contains antioxidant components that may help resilience to physical stress and support immune health during training. These functions fit with everyday physiological processes described for adaptogenic mushroom blends.

This product isn't meant to diagnose, treat, cure, or prevent any disease.

Efectiv Nutrition is the brand we choose for PeakO2 Unflavoured because of its straightforward, transparent model and strong standing in the UK sports nutrition landscape. As a UK-based brand recognised for sourcing branded, research-backed ingredients such as PeakO2, it has built a reputation for clarity and reliability, which aligns with our commitment to trust and safety.

This brand uses premium, branded ingredients produced to high standards, with PeakO2 sourced from Compound Solutions and manufactured in the USA under organic conditions. Our team evaluates brands against clear criteria for quality, traceability and consistency, and Efectiv Nutrition consistently meets these expectations while emphasising product integrity and openness to third party scrutiny via its ingredient partners.

This partnership is grounded in our belief that disciplined quality practices and a positive manufacturing ethos drive reliable performance support. We evaluated the brand with our medical experts to ensure alignment with our our team of medical experts and our supplement quality standards. The result is a product-forward collaboration that fits PeakO2’s profile and Welzo’s quality benchmarks.