Growth-factor serums and peptide serums sit on the same shelf and aim at the same thing: skin that looks firmer and smoother over time. They are built differently, though, and one of them, ZO Growth Factor Serum, also contains retinol, which changes where it goes in your routine. Here is how the formulas we carry compare, in plain cosmetic terms.
Growth factors and peptides, in plain terms
- Peptides are short chains of amino acids, the same units that proteins are made of. In skincare they are used to support the look of firmer, smoother skin. Some brands use a named blend, such as Alastin's TriHex Technology.
- Growth factors are proteins. On a label you will see them as growth-factor ingredients or a named complex, such as ZO's ZPRO complex or SkinMedica's TNS complex, usually paired with peptides.
Neither is a quick fix. The descriptions for these serums talk about benefits that build with consistent use, morning and evening or every night.
The serums side by side
| Serum | Built around | When | How much |
|---|---|---|---|
| ZO Growth Factor Serum | Plant- and enzymatically-derived growth-factor ingredients, retinol and amino acids, with the ZPRO complex and peptides | Evening | One pump |
| Alastin Restorative Skin Complex | TriHex Technology, Alastin's patented peptide blend | Morning and evening | Apply to clean skin |
| Alastin Regenerating Skin Nectar | TriHex Technology with naringenin, arnica and a botanical complex | Morning and evening | 1 to 2 pumps |
| ZO Firming Serum | Multi-peptide complex, including palmitoyl tripeptide-1 and palmitoyl tetrapeptide-7; doesn't rely on retinol | Morning and evening | 3 to 4 drops |
| SkinCeuticals P-TIOX Serum | 10% blend of three peptides | Morning and evening | 4 to 5 drops |
| SkinCeuticals Advanced RGN-6 | 6.7% RGN complex, with a stabilized peptide blend and hyaluronic acid | Morning and evening | 2 to 3 drops |
| Skinbetter Science InterFuse Intensive Treatment Lines | Neuropeptides with hydrating ingredients | Morning and evening, on specific areas | A small amount |
Growth-factor serums
ZO Growth Factor Serum
A lightweight evening serum that combines plant- and enzymatically-derived growth-factor ingredients with retinol and amino acids, plus ZO's ZPRO complex with peptides, Buddleja stem cells and angelica polymorpha root extract. With consistent use, it helps skin look firmer, fuller and denser, with a more even-looking tone. Press one pump into clean skin every evening. Because it contains retinol, count it as your retinol step: if you also use a separate retinol, alternate the two. A bottle typically lasts about 10 weeks with nightly use.
For the eye area
ZO Growth Factor Eye Serum brings the ZPRO complex to the eye area, with peptides, hyaluronic acid and caffeine for the look of morning puffiness. SkinMedica TNS Eye Repair brings the TNS growth-factor complex to a richer eye base, with peptides, hyaluronic acid, squalane and ceramides. Both are used morning and evening: pat a small amount around the orbital bone with your ring finger, and wear SPF over it during the day.
Peptide serums
Alastin Restorative Skin Complex vs Regenerating Skin Nectar
Both are built around TriHex Technology, Alastin's patented peptide blend, and both are used morning and evening.
- Restorative Skin Complex is the versatile everyday step, for the look of firmer, smoother, more radiant skin. It has a lightweight, fast-absorbing texture and works on its own or under moisturizer and SPF.
- Regenerating Skin Nectar pairs TriHex Technology with naringenin, arnica and a botanical complex. It is made for mature complexions looking for visibly firmer, more elastic-looking skin and a more even-looking tone. Apply 1 to 2 pumps; the firming and tone benefits build gradually.
If your priority is skin that feels stressed or sensitive, Alastin INhance Serum uses TriHex Technology in a soothing, lightweight formula for everyday use.
ZO Firming Serum
A featherweight peptide serum with a multi-peptide complex that includes palmitoyl tripeptide-1 and palmitoyl tetrapeptide-7, plus antioxidants and humectants. It helps support the look of firmness and definition along the jawline, cheeks and mid-face. It does not rely on retinol, which makes it suitable for daytime use and for skin that feels sensitive to vitamin A derivatives. Apply 3 to 4 drops morning and evening, before moisturizer; if you use retinol in the evening, apply Firming Serum first and layer the retinol on top.
For expression lines: P-TIOX and InterFuse Intensive Treatment Lines
Both are made for the look of expression lines on the forehead, between the brows and around the eyes.
- SkinCeuticals P-TIOX uses a 10% blend of three peptides: acetyl hexapeptide-8, acetyl heptapeptide-1 and dipeptide diaminobutyroyl benzylamide diacetate. Press 4 to 5 drops into the areas where expression lines form, morning and evening, and follow with moisturizer and SPF during the day.
- Skinbetter Science InterFuse Intensive Treatment Lines is a concentrated serum with neuropeptides and hydrating ingredients, made with Skinbetter Science's InterFuse technology. Apply a small amount directly to the areas you want to focus on, morning and evening, before moisturizer.
SkinCeuticals Advanced RGN-6
A featherweight serum built around a proprietary 6.7% RGN complex, with hyaluronic acid and a stabilized peptide blend, for the look of fine lines, firmness and smoothness. It is designed to go on first: press 2 to 3 drops into clean skin morning and evening, under vitamin C in the morning and under retinol in the evening. It suits anyone who wants a serum for these concerns without overlapping the retinol or AHA steps in their routine.
Peptides in moisturizers
If you would rather not add a serum, peptides also come in creams. Skinbetter Science InterFuse Treatment Cream Face & Neck pairs a peptide and amino acid complex with hyaluronic acid and niacinamide, for the face and neck in one step. SkinCeuticals A.G.E. Interrupter Advanced pairs proprietary peptides with wild blueberry extract in a rich moisturizer formulated with mature skin in mind.
How to layer them
- Thinnest first: watery serums before creams. Where a label asks to go first, as RGN-6 does, follow it.
- Morning: cleanse, serums, moisturizer, then SPF. The peptide serums can all be part of a morning routine; ZO Growth Factor Serum is an evening product.
- Evening: cleanse, peptide serum, retinol if you use one, moisturizer. On nights you use ZO Growth Factor Serum, it is your retinol step.
- One change at a time: add one new serum, give it a couple of weeks, then add the next, so you know how your skin responds to each.
How to choose
- An evening serum that also counts as your retinol: ZO Growth Factor Serum.
- An everyday peptide serum: Alastin Restorative Skin Complex.
- Mature skin, with firmness and even-looking tone as the focus: Alastin Regenerating Skin Nectar.
- A peptide serum that doesn't rely on retinol, for day or night: ZO Firming Serum.
- Expression lines: SkinCeuticals P-TIOX or InterFuse Intensive Treatment Lines.
- The eye area: ZO Growth Factor Eye Serum or SkinMedica TNS Eye Repair.
Browse growth factors and peptides, fine lines and firmness, ZO Skin Health serums or the full Alastin range. For how peptides fit alongside vitamin C and retinol, read vitamin C, retinol and peptides.
Related guides: retinol strengths explained, hyaluronic acid serums compared and the ZO Skin Health routine.