Rejuran works by delivering a highly purified form of polynucleotide (PN) molecules directly into the dermis, where they act as signaling agents to stimulate your skin’s own natural repair mechanisms, enhance collagen production, improve hydration, and reduce inflammation, ultimately leading to stronger, healthier, and more resilient facial skin. Think of PN molecules as a set of detailed instructions that tell your skin cells to stop behaving like aged or damaged tissue and start functioning like youthful, healthy tissue again. The core of its action isn’t about adding a foreign substance but about restarting and optimizing processes that have slowed down due to age, sun exposure, and environmental damage.
To truly grasp how this happens, we need to dive into the science of skin damage and the specific properties of the PN molecules in rejuran.
The Science of Skin Damage: What Are We Actually Repairing?
Our skin’s strength and youthfulness come primarily from the dermis, the thick layer of tissue beneath the surface. This is where you find collagen and elastin—the protein fibers that create a firm, supple, and elastic structure. Think of collagen as the steel scaffolding of a building and elastin as the rubber bands that allow it to bounce back. Over time, this support system breaks down. By the time we reach our 30s, we naturally lose about 1% of our collagen per year. But external factors massively accelerate this process.
- UV Radiation: Up to 80% of facial aging is attributed to sun exposure. UV rays create enzymes called matrix metalloproteinases (MMPs) that actively break down collagen fibers in a process called photoaging.
- Glycation: When sugar molecules bind to proteins like collagen, they form advanced glycation end products (AGEs). These make collagen stiff, brittle, and unable to repair itself. A study in the British Journal of Dermatology found that AGEs accumulate significantly in the skin from the age of 20 onwards.
- Inflammation: Chronic, low-grade inflammation from stress, pollution, and diet constantly signals the skin’s repair systems to be on high alert, leading to disorganized and inefficient healing.
The result is a dermis that is thinner, weaker, and filled with fragmented, disorganized collagen. This manifests on the surface as wrinkles, sagging, large pores, and a rough texture. Traditional treatments often try to flood the area with new collagen, but Rejuran’s approach is smarter: it focuses on repairing the cellular environment so the skin can produce high-quality, well-organized collagen on its own.
The Power of Polynucleotides: The “Instruction Manual” for Skin Cells
Polynucleotides are long chains of nucleotides, the building blocks of DNA and RNA. The PN used in Rejuran is sourced from salmon DNA and purified to an exceptionally high degree (over 99%) to ensure safety and biocompatibility. These molecules are not genetically active; they don’t alter your DNA. Instead, they function as biological signaling molecules. Once injected into the dermis, they perform several critical functions simultaneously.
1. Fibroblast Activation and Enhanced Collagen Synthesis: Fibroblasts are the cells in your dermis responsible for producing collagen, elastin, and hyaluronic acid. As we age, fibroblasts become sluggish and less productive. PN molecules have been shown to bind to specific receptors on fibroblasts, effectively “waking them up.” A 2019 study published in the Journal of Cosmetic Dermatology demonstrated that PN stimulation increased Type I collagen production in human fibroblasts by over 200% compared to untreated cells. This isn’t just more collagen; it’s the right kind of collagen. The table below breaks down the key differences in collagen quality.
| Factor | Natural Aging/Photoaged Skin | Rejuran-Stimulated Skin |
|---|---|---|
| Collagen Density | Low, fragmented fibers | High, dense network of fibers |
| Collagen Organization | Disorganized, chaotic | Well-organized, parallel bundles (like young skin) |
| Elastin Quality | Elastosis (degenerated elastin) | Improved elastin fiber structure and function |
2. Intense Deep Hydration and Tissue Regeneration: PN molecules are hydrophilic, meaning they attract and bind water. A single PN chain can hold a significant amount of water, creating a hydrated gel-like matrix in the dermis. This does two things: it plumps the skin from within, reducing the appearance of fine lines, and it creates an optimal fluid environment for cells to move, communicate, and repair themselves. This is akin to providing a well-watered garden for seeds to grow, rather than trying to plant in dry, cracked earth.
3. Powerful Anti-Inflammatory and Antioxidant Effects: Inflammation is a primary driver of skin degradation. Research has shown that PN can downregulate pro-inflammatory cytokines like TNF-α and IL-6 by up to 40-60%. Furthermore, they enhance the skin’s antioxidant defense system, helping to neutralize free radicals generated by UV exposure and pollution. This calming effect is why Rejuran is also highly effective for repairing sensitive skin, redness, and acne scars, as it helps to “reset” the skin’s inflammatory response.
The Treatment Process and Long-Term Structural Changes
A typical Rejuran treatment protocol involves a series of 3-4 sessions, spaced about 4 weeks apart. This isn’t a one-and-done filler; it’s a regenerative process. The initial injections deliver the PN “instructions.” Over the following weeks, your fibroblasts get to work. The real magic happens in the subtle, cumulative improvements in skin quality rather than an immediate dramatic volume change.
- Week 1-2: The deep hydration effect is often the first noticeable change. Patients report a “glow” and improved skin texture as hydration levels rise.
- Week 3-4: The collagen and elastin synthesis process is in full swing. This is when skin elasticity and firmness begin to improve measurably. Studies using cutometry (a device that measures skin elasticity) have shown elasticity improvements of 15-25% after a full treatment course.
- Month 2-3 and Beyond: The newly formed collagen network matures and reorganizes. This leads to a reduction in pore size (as the surrounding skin tightens), improved scar tissue quality, and a strengthening of the skin’s barrier function. The results are long-lasting because you’ve fundamentally improved the health of the skin matrix. Clinical follow-ups show results can be maintained for 12 months or longer, especially with good skincare and occasional maintenance treatments.
The key data point is the increase in dermal density. Ultrasound imaging of the skin before and after treatment clearly shows a thickening of the dermal layer. One clinical trial observed an average dermal thickness increase of approximately 18% after three sessions, which is a direct indicator of a stronger, more resilient skin structure.
Rejuran vs. Other Common Treatments: A Comparative Advantage
It’s helpful to position Rejuran against other popular procedures to understand its unique value.
- Vs. Hyaluronic Acid (HA) Fillers: HA fillers are great for replacing volume and filling deep folds. They work by physically occupying space. Rejuran doesn’t add significant volume; it improves the quality of the tissue that’s already there. It’s the difference between patching a hole in a wall (filler) and reinforcing the entire wall’s structure to prevent future holes (Rejuran). Many practitioners use them together for a comprehensive result.
- Vs. PDO Threads: Threads provide an immediate mechanical lift. Rejuran provides a biological “lift” by strengthening the skin’s foundation. Threads can trigger some collagen production around the thread material, but Rejuran offers a more global and uniform stimulation of the entire treated area.
- Vs. Laser Treatments: Lasers like fractional CO2 work by creating controlled micro-injuries to force a healing response. This can be effective but often involves significant downtime. Rejuran promotes healing without the same level of initial tissue destruction, leading to minimal downtime—typically just some redness and swelling for 24-48 hours.
The mechanism of Rejuran is fundamentally about bio-regeneration. It leverages the body’s innate intelligence to heal itself, providing the specific signals that aging skin has forgotten how to send. By targeting the root causes of skin degradation—diminished cellular communication, inflammation, and loss of structural integrity—it doesn’t just mask problems; it actively works to reverse them, creating skin that is not just better-looking but functionally stronger and healthier.