The short version: before red light therapy, use clean skin and lightweight, photostable products that let the light through, such as a hydrating serum with stabilised actives. Save rich creams and any unstable ingredients, especially unstabilised vitamin C and exfoliating acids, for after your session or a different time of day. Getting the sequence right means the light reaches your skin efficiently and your actives work when they are actually effective.
Red light therapy is not a standalone step you bolt onto your routine. It sits inside it, and what you put on before and after either helps or gets in the way. This guide walks through the full sequence: what to apply first, what to keep on during treatment, what to save for after, and the one common mistake that quietly wastes good products.
Start with clean, bare skin
Always begin a session on freshly cleansed skin. This is the single most important prep step, because anything sitting on the surface can absorb or scatter light before it reaches the cells you are trying to treat.
Makeup, sunscreen, and heavy or oily products form a physical layer between the light and your skin. Cleanse thoroughly and pat dry, then build back up in the right order. Bare, clean skin is the blank canvas that lets every following step do its job, both the light and the skincare.
What to apply before: light, absorbable, photostable
Before the light, you want thin layers that absorb quickly and stay stable under light and gentle heat. Think hydrating, barrier-supporting serums with actives that will not degrade, not thick occlusive creams that block the light.
Two ingredient qualities matter here. First, absorbency: a lightweight serum sinks in and does not sit on the surface as a barrier. Second, stability: the active has to survive light and warmth without breaking down. INFERA's Source, with PDRN and multi-weight hyaluronic acid, is a good pre-session layer because it hydrates and supports the barrier while absorbing cleanly. Obsess C is also pre-session compatible, because its vitamin C is in a stabilized form, sodium ascorbyl phosphate, that holds up under light and heat rather than oxidizing. Hydration before a session is worth prioritizing, since well-hydrated skin is a better medium for even light delivery.
During the session: the glide layer
Some devices, including INFERA's, use a glass applicator that moves across the skin, so you need a smooth interface between the device head and your face. This is a specific job, and it calls for a specific product.
INFERA's Lightsync is designed for exactly this moment. Its silicone-based formula lets the glass applicator glide without drag, while its botanicals, Centella, green tea, and licorice root among them, are photostable and non-sensitising at 625nm and 850nm. It is applied to the skin or directly to the applicator head during treatment, not before or after as a regular serum. Think of it as the interface layer between device and skin rather than a step you absorb.
What to avoid before a session
Skip anything that is unstable under light or that makes skin more sensitive. This is where good products can go to waste, or worse, cause irritation, simply because of timing.
The clearest example is unstabilised vitamin C, or L-ascorbic acid. It is a genuinely effective antioxidant, but it is also notoriously unstable, oxidizing and losing its biochemical properties in the presence of light, heat, and oxygen [1][2]. Putting it under a warm light device is close to the worst-case scenario for it: you degrade the active and get little benefit. Researchers who work on ascorbic acid formulation even recommend nighttime use and cool storage to preserve it [2]. This is why INFERA's Hyaluronic Boosting Serum, which uses unstabilised ascorbic acid, is best saved for routines that do not involve a same-session device treatment, rather than applied beforehand.
Two other categories to hold back before a session: exfoliating acids like AHAs and BHAs, and retinoids. Exfoliating acids increase skin sensitivity, and retinoids break down under light, so both are better suited to non-device evenings. Save them for a different night, and never layer an exfoliating acid immediately after a session, when skin is more reactive.
What to apply after: repair and seal
After the light, your skin is prepped to make the most of richer, reparative products. This is the moment for the nourishing creams you deliberately kept off beforehand.
Once the session is done, follow with your more substantial repair steps. INFERA's Hero, an exosome and CoQ10-rich cream, works well as a final repair layer, with Deep around the eyes. In the morning, always finish with SPF, since sun protection remains the highest-value habit for long-term skin health. If you want to use that unstabilised vitamin C serum, an evening that does not include a device session is its place, so the active stays intact.
A simple before, during, and after routine
Here is the sequence in order for an evening device session:
- Cleanse thoroughly and pat dry.
- Apply Lightsync to skin or the applicator head, then run your INFERA device.
- Follow with Obsess C, pressing in 3 to 4 pumps and letting it absorb.
- Seal with Hero as your repair step, and Deep around the eyes.
- On non-device nights, this is where exfoliating acids or the unstabilised vitamin C serum can fit instead.
The logic never changes: clean skin first, light and stable layers around the light, rich repair after, and unstable or sensitizing actives moved to a different time.
Frequently Asked Questions
Should you apply skincare before or after red light therapy?
Both, but different products at each stage. Before, use clean skin plus lightweight, photostable serums that absorb well and let light through. After, apply richer repair creams and always finish with SPF in the morning. Unstable ingredients like unstabilised vitamin C and exfoliating acids should be saved for after a session or a non-device day.
Can you use vitamin C before red light therapy?
It depends on the form. Stabilised vitamin C, such as sodium ascorbyl phosphate, is fine before a session because it holds up under light and heat. Unstabilised L-ascorbic acid is not, because it oxidizes and loses effectiveness when exposed to light and warmth [1][2]. Save unstabilised vitamin C for an evening without a device session.
What should you not use before red light therapy?
Avoid unstabilised vitamin C, exfoliating acids like AHAs and BHAs, retinoids, and heavy occlusive or oily products. The unstable actives degrade under light and heat, the acids and retinoids can increase sensitivity, and thick creams block light from reaching the skin. Clean, lightly hydrated skin is the ideal starting point.
Do you apply serum before or after red light therapy?
A lightweight, stable, hydrating serum can go on before to support even light delivery, as long as it absorbs fully and does not sit as a barrier. More substantial serums and creams, and any unstable actives, are better applied after the session. The rule is: thin and stable before, rich and reparative after.
What should you put on after red light therapy?
After a session, apply your richer repair products, such as a peptide and antioxidant cream, then eye cream, and finish with SPF in the morning. This is also when you can layer nourishing ingredients you kept off beforehand. Avoid exfoliating acids immediately afterward, as skin can be more reactive right after treatment.
The sequence that makes it work
Red light therapy rewards a little planning. Clean skin lets the light through, stable and lightweight layers support it without blocking it, rich repair products land best afterward, and unstable actives like unstabilised vitamin C or exfoliating acids belong on a different night. Get that order right and every session, and every product, works closer to its potential. INFERA's range is built around this exact sequence, from the Lightsync glide layer to the stabilized actives designed to sit safely alongside light.Â
Sources
- Abric E, et al. Anti-Spot, Lightening Effect and Cutaneous Acceptability of a Stable Anhydrous Ecobiological Formulation of 10% L-Ascorbic Acid. Clinical, Cosmetic and Investigational Dermatology, 2024.
- Costa de Oliveira A, et al. New discoveries of the action of L-ascorbic acid (vitamin C): Enhanced efficacy in formulations. Brazilian Journal of Pharmaceutical Sciences, 2025.