Forest of the Borges's EGF Serum Epidermal Growth Factor - Epidermal Growth Factor for Post-Treatment Skin Recovery and Rejuvenation

"One Ingredient. One Job. Nothing Added That Doesn't Need to Be There."

There is a kind of formula I trust before I've even applied it. Six ingredients. One active. A concentration listed on the label. My name is Yuki. I write songs, I work at a record café in Seongsu-dong, and my skincare approach is the same as my approach to a track: the fewer elements competing for space, the clearer each one is heard. My skin runs dry and sensitive, which means any new product requires a patch test and three days of patience before I commit. Formulas with ten actives and no clear hierarchy make that impossible.

This serum is the opposite of that. Water, Butylene Glycol, Glycerin, 1,2-Hexanediol, Hydrogenated Lecithin, rh-Oligopeptide-1 at 1ppm. That is the complete ingredient list. The rh-Oligopeptide-1 is a synthetic polypeptide - the EGF component - and it is the only active in the formula. Everything else is carrier, humectant, and delivery support. For dry sensitive skin that needs to know exactly what it is being asked to accept, this kind of transparency is not a small thing.

What is rh-Oligopeptide-1, and what is its role in a skincare serum?

rh-Oligopeptide-1 is the INCI name for recombinant human Epidermal Growth Factor - a synthetic polypeptide that mirrors a protein naturally present in the body. In the context of this cosmetic serum, it is present at 1ppm (one part per million), which is the concentration level stated on the label. EGF as a polypeptide is classified as a cosmetic ingredient in this formula, meaning it functions at the surface and superficial skin level in a cosmetic context. The formula is explicitly for external cosmetic use only and carries no medical or pharmaceutical designation. The amber glass dropper bottle protects the formula from light degradation, which is a relevant packaging decision for polypeptide stability.

🌙 Yuki's Note: rh-Oligopeptide-1 - the INCI name for recombinant human Epidermal Growth Factor (EGF), produced through biotechnology to mirror a naturally occurring human protein. The "rh" prefix stands for recombinant human, meaning it is synthetically produced rather than derived from biological sources. In cosmetic formulas, it is classified as a skin-conditioning active.

Also Worth Considering:

Hydrogenated Lecithin - a phospholipid emulsifier derived from soy or sunflower, used here as a delivery component. Phospholipids are structurally similar to the skin's own lipid bilayer, which makes them effective at helping water-soluble actives reach the upper skin layers. Its presence alongside rh-Oligopeptide-1 is a deliberate delivery decision.

Also Worth Considering:

How is this serum used - directly on skin or mixed into other products?

Both options are designed into this formula. Applied directly, a few drops are smoothed onto cleansed skin and absorbed before the next step. The recommended use level is 10% of the combined product - meaning if mixed into an existing serum, lotion, or cream, the EGF serum should make up approximately one part in ten of the final mixture. This mixing capability is what distinguishes this from a standard single-use serum: it functions as a standalone step or as a concentrated addition to formulas already in the routine. The dropper format with the anti-spill inner cap supports precise application in both use cases.

Is this suitable for sensitive skin, and what does the patch test recommendation mean in practice?

The formula contains no fragrance, no essential oils, no alcohol, and no synthetic dyes - the primary variables that drive sensitivity reactions in most serums. The ingredient list is six items, which means the number of potential irritants is structurally low. The patch test recommendation on the label is not a warning that the formula is likely to cause reactions - it is standard cosmetic guidance, and particularly sensible for any new active ingredient regardless of how gentle the formulation appears. Apply a small amount to the inner arm or behind the ear, leave for 24 hours, and proceed to full-face use if no reaction occurs. For dry sensitive skin that reacts to new products, this is the step that converts a risk into a known.

Can this be used morning and night, and where on the face and body is it appropriate?

The formula is designed for flexible daily use. Application areas listed in the source include the face (cheeks, under-eye area), hands, and any area of the body where skin regeneration support is desired - with the exception of the lips and direct eye contact. The serum is fragrance-free and designated as suitable for all skin types, including sensitive. For morning use, following with broad-spectrum SPF is standard practice when applying any serum active to ensure UV protection is in place. Evening application can serve as the active step before a richer moisturiser or sleeping cream in a dry skin routine.

How should this be stored, and what is the shelf life after opening?

The amber glass bottle is the relevant storage detail: amber glass blocks UV light, which can degrade polypeptide stability over time. Store away from direct sunlight and in a dry place, consistent with standard cosmetic storage guidance. The period after opening is 24 months from the manufacture date printed on the bottle. The anti-spill inner cap is a practical feature for the dropper format - replacing it securely after each use maintains both hygiene and formula integrity across the full 24-month window.

Worth Knowing

Six Ingredients Is a Design Choice: The complete formula - Water, Butylene Glycol, Glycerin, 1,2-Hexanediol, Hydrogenated Lecithin, rh-Oligopeptide-1 - contains one active and five supporting components. For sensitive skin evaluating a new product, a short ingredient list means a short list of variables to assess. If a reaction occurs, identifying the cause is straightforward. If no reaction occurs, the active ingredient gets full credit.

1ppm Is the Stated Concentration: rh-Oligopeptide-1 is present at 1ppm in the formula as supplied. The recommended use level of 10% means that in a mixed application, the final EGF concentration is 0.1ppm. The source states the formula at the 10% dilution delivers 10ppm of EGF - this refers to using it at 10% of a combined mixture, not applying the full serum at 10x concentration. Understanding this ratio matters before calculating how to incorporate it into an existing routine.

The Mixing Function Changes How This Fits a Routine: Most serums are designed for standalone use. This one is explicitly designed to be mixed into existing products - a lotion, emulsion, or moisturiser at home. For a minimalist routine that already has the hydration and barrier steps covered, this format allows adding a single targeted active without adding a new separate step.

Amber Glass Protects Polypeptide Stability: Polypeptides can degrade with UV exposure over time. The amber glass bottle is a packaging decision that directly addresses this. Storing the bottle away from light and heat maintains the formula's integrity across its 24-month post-opening window. Clear glass or plastic packaging would not offer the same stability protection for this type of active.

This Is a Cosmetic Product, Not a Pharmaceutical One: The source states explicitly and repeatedly that this is for cosmetic use only, not for medical or pharmaceutical purposes. It is designed for external application to intact skin as part of a regular skincare routine. It is not intended for use on broken, compromised, or post-procedure skin in a medical context.

Patch Testing Before Full-Face Application: The product recommends a patch test before use. For a formula this minimal, the test takes 24 hours and removes the uncertainty of introducing a new active. Apply to the inner arm or behind the ear, wait 24 hours, proceed if no reaction occurs. For sensitive skin that tends to react to new ingredients, this step converts unknown into known before anything goes on the face.

*Six ingredients. One active. A concentration you can read on the label.

Most formulas ask you to trust the combination. This one asks you to trust one thing at a time - which is, actually, the only way I trust anything.

The dropper. The amber glass. The fact that nothing is hiding in a long ingredient list. For sensitive skin that patches everything first and decides slowly, this is the kind of formula that makes that process simple. 🌙*