Description

Pen Content: YK-11 – 80mg, RAD-140 – 80mg, MK-677 – 80mg, OTR-AC – 50mg

What is the Bulking Stack?

Bulking Stack is a stabilized, pre-formulated subcutaneous pen containing four synergistic compounds: YK-11, RAD-140 (Testolone), MK-677 (Ibutamoren), and OTR-AC. This combination is designed for research protocols focused on maximizing muscle mass, strength, recovery, and regeneration—without directly affecting classical hormonal axes.

It contains a total of 290mg of active ingredients in 3ml, formulated for high bioavailability when used subcutaneously for scientific purposes, ensuring stability and accurate dosing in experimental conditions.

Key Components and Mechanism of Action:

YK-11 is a unique SARM structurally based on DHT, with potential myostatin inhibition via increased follistatin expression. This makes it particularly valuable in research protocols aiming for hypertrophy beyond physiological limits. YK-11 exhibits partial androgenic activity combined with gene activation related to cellular growth and may support rapid and pronounced muscle mass gains.

RAD-140 (Testolone) is a potent selective androgen receptor modulator that activates receptors in skeletal muscle tissue without affecting other hormone-sensitive tissues. RAD-140 has been studied for its ability to stimulate protein synthesis, increase strength, and enhance recovery following high physical loads. Its combination with YK-11 provides a comprehensive anabolic response.

MK-677 (Ibutamoren) is a ghrelin receptor agonist and GH–IGF-1 axis activator that increases growth hormone and IGF-1 secretion without suppressing the androgenic axis. MK-677 supports nitrogen retention, enhances tissue repair, improves sleep quality, and aids regeneration—making it an essential component in protocols focused on long-term muscle building.

OTR-AC complements the stack with targeted action on muscle density and definition without fluid retention. It shows high selectivity toward muscle tissue and is suitable for enhancing outcomes under deficit or low-recovery conditions, without estrogenic activity.

Synergistic Effect of the Bulking Stack:

The combination of YK-11 and RAD-140 delivers a highly potent anabolic stimulus, while MK-677 supports hormonal and cellular regeneration. OTR-AC contributes to visual muscle density and the preservation of results under various metabolic conditions. This formula is aimed at maximizing muscle mass, strength, and structural integrity, delivering a balanced response between androgenic activation and hormonal support.

The synergy between the four compounds allows for reduced individual dosages while enhancing overall effectiveness, making it ideal for advanced research protocols with a strong anabolic focus.

Scientifically Supported Potential Benefits:

The Bulking Stack formula is designed to deliver pronounced hypertrophy supported by hormonal and receptor regulation. The stack addresses key objectives in scientific protocols focused on growth, density, and functional recovery.

• Creates conditions for optimized muscle growth through enhanced anabolic stimulation
• Supports accelerated regeneration and tissue repair
• Maintains an anabolic environment via IGF-1 and GH pathways
• Improves sleep quality and recovery, essential for long-term muscle development
• Stimulates visual density and dry muscle definition without water retention
• Suitable for intensive lab cycles assessing muscle growth capacity and metabolic adaptation

Dosage and Use in Research Protocols:

Recommended research protocol: 10 units once daily, for a duration of 4–8 weeks, followed by a rest period of 3–5 weeks.

Total pen content: 300 units

Maintaining optimal dosage and monitoring application duration play a crucial role in limiting the manifestation of side effects.

Possible Side Effects:

Currently, there is insufficient published clinical data regarding long-term usage profiles. In laboratory settings, tolerability is generally good, but as with any compound administered subcutaneously, individual reactions cannot be excluded.

Potential local effects related to the application method may include redness, sensitivity, discomfort, or mild swelling at the injection site. In longer cycles and higher doses, some models have explored possible effects on endogenous hormonal regulation, which may vary depending on dosage, duration, and individual sensitivity.

Strict monitoring of both dosage and duration is recommended for all research protocols.

For laboratory purposes and personal observation only.