Face Serums: The Format Built to Carry Actives

A face serum is not a thinner moisturizer. It is a delivery format built for one job: carrying a high load of active ingredients to where they work, without the texturizing agents that weigh a cream down. The fluidity is not a comfort feature: it is what the formula costs. This collection brings together the face serums from the professional and medical-grade lines we use in the treatment rooms at Spa Infinima, our skincare centre in the Quebec City region. There are two ways to read it: by active ingredient (hyaluronic acid, vitamin C, retinol, niacinamide, peptides) or by skin concern. Neighbouring formats have collections of their own: ampoules for short courses, moisturizers to seal, masks for targeted treatment, and eye care for an area that needs a texture of its own. The full range sits in our facial skincare collection.
Learn more about face serums

What a Serum Does That a Moisturizer Cannot

The difference is purpose, not viscosity. A moisturizer works at the surface: it supplies lipids, limits water loss and closes the skin barrier. A serum carries a high concentration of actives in a light vehicle, designed to move through the upper layers rather than sit on them. Hence the sequencing rule: serum before cream, never the reverse. Applied over a film that is already in place, a serum crosses nothing and its actives are wasted. The serum targets, the cream seals, and the two together beat either one doubled. If your routine can only carry one active product, the serum is the one that shows.

Serum, Ampoule or Concentrate: Three Formats, Three Jobs

The three words get used interchangeably. They are not the same thing.
Format What defines it Rhythm
Serum Active concentrate in a pump or dropper bottle, dosed for continuous use Daily, morning, evening or both
Ampoule Sealed single dose, higher concentration, no surplus preservative 7- to 28-day course, following a professional treatment
Concentrate Heavily loaded formula on a single axis — firmness, radiance, soothing As a booster, alone or under your usual serum
The face ampoule is the course format: you run it over a set period, often after a treatment or ahead of an event, then return to your maintenance serum. It does not replace the serum. It intensifies it over a short window.

Choosing a Face Serum by Active Ingredient

This is the most reliable way into the collection. Each active answers a specific mechanism, and most disappointments come from a good product chosen for the wrong need.

Hyaluronic Acid, Vitamin C and Retinol

Hyaluronic acid holds water in the upper layers. It suits every skin type, oily included, because it hydrates without adding lipids. It is the first serum to try when skin feels tight but is not dry. Vitamin C is an antioxidant: it limits free-radical damage, revives radiance and softens the look of dark spots. Wear it in the morning, under your sun protection, whose work it complements and never replaces. Retinol acts on surface renewal: it smooths the look of fine lines and refines skin texture. Introduce it slowly: two evenings a week to start, and never the same week as a new exfoliant. Passing redness early in a course is common; irritation that settles in means the pace is too fast.

Niacinamide, Peptides and the Glycolic Acid Serum

Niacinamide is the all-rounder: it limits excess oil, tightens the look of pores and calms the look of redness. It is often the best entry point for skin that tolerates neither vitamin C nor retinol. Peptides and collagen work on support and suppleness: the territory of firming serums. Squalane and ceramides work on comfort rather than performance: they support the skin barrier of skin tested by a dry winter or an over-active routine. The glycolic acid serum belongs to chemical exfoliation: glycolic acid is an AHA that loosens surface cells and works on texture and radiance. Our acid exfoliation formulas live in the scrubs and exfoliants collection rather than here: same logic of active, different family of care, and it does not layer with retinol on the same evening. Our article on how to work vitamin C, hyaluronic acid and niacinamide into your routine sets out the pairings that work, and the two or three worth avoiding.

Not Sure Which Active Suits You?

A professional skin analysis costs less than a serum chosen wrong. Your esthetician reads your skin, decides between two actives and builds the sequence, and every order gives you $20 toward a treatment.

Choosing a Serum by Skin Concern

The other way in, for anyone who already knows their ground. The same active does not behave the same way on skin that shines and skin that reacts.

Serum for Oily Skin and Breakout-Prone Skin

Oily skin does not need to be stripped, it needs to be regulated. A fluid serum with niacinamide or salicylic acid reduces the look of enlarged pores and limits shine without triggering the rebound oil production that harsh stripping causes. Our oily skin, combination skin and acne-prone skin collections carry the same logic further.

Serum for Sensitive and Reactive Skin

Sensitive skin reacts to fragrance, alcohol and blunt concentrations. The useful instinct is the opposite of intuition: fewer actives, better chosen, introduced one at a time. Soothing serums lean on plant extracts and skin barrier support rather than performance. See also the sensitive skin, dry skin and dehydrated skin collections: dehydration affects oily skin too, since it is a condition, not a type.

Brightening Serum for a Dull Complexion

A brightening serum does not lighten skin: it evens the complexion and revives luminosity in tired skin. Vitamin C, antioxidants and spot-targeting actives dominate here. A dull complexion is rarely about pigment alone: congested skin texture reflects light poorly, which is why a weekly exfoliant often doubles what a brightening serum delivers. The pigmented skin collection handles established dark spots.

Firming Serum and Loss of Firmness

A firming serum targets suppleness and support, not the isolated wrinkle. Peptides, collagen and firming complexes work on the skin's structure; judge the result over several weeks, not one application. This is the register of our first signs of aging and mature skin collections, where the serum precedes a richer cream. For a full tour, the shop by skin type collection gathers all of these entry points.

The Serum Brands We Use at Spa Infinima

Our selection rule fits in one sentence: we only sell what we use professionally. That is what explains the absence of certain brands you will find everywhere else. Swiss high-end skincare (Valmont, Swiss Line, Cellcosmet) works with cellular extracts and firming complexes. Professional anti-aging rests on Babor and its ampoule concentrates, Payot, Yon-Ka and Quebec manufacturer G.M. Collin. The biomimetic approach comes from Esthederm. For skin already used to strong actives, iS Clinical, IMAGE Skincare, Jan Marini, Luzern, Aquafolia and Vivier sit in medical-grade territory: higher concentrations, backed by clinical studies.

How to Apply a Face Serum

The gesture matters nearly as much as the formula, because a serum placed wrong in the order does nothing at all. On clean, still slightly damp skin, after your cleanser and toner: three or four drops cover the face, neck and décolletage. Press rather than rub, let it absorb for a few seconds, then follow with eye care, your moisturizer, and in the morning your sun protection. Lip care closes the routine. Two serums can be layered, thinnest to thickest, but rarely more than two, and never two actives pulling the same way. Vitamin C in the morning, retinol at night: the simplest and safest pairing there is. For everything below the jawline, our body collection takes over. Judge a serum over six to eight weeks. Below that, you are mostly measuring novelty.

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Our advisors answer before you buy, not after. Describe your skin and your two priorities: we will recommend one serum, not a list of six. Our gift sets already pair several steps from the same line.

Frequently Asked Questions About Face Serums

What is the difference between a serum and a face ampoule?

A serum is a daily maintenance product: it keeps for several weeks and supports the routine continuously. A face ampoule is a sealed single dose, more concentrated and without surplus preservative, designed for a course of seven to twenty-eight days. You use the ampoule after a professional treatment or ahead of an event, then return to your serum. The two formats complement each other rather than replace one another.

When in the routine should a face serum be applied?

After cleansing and toner, on skin that is still slightly damp, and before your moisturizer. The order runs thinnest to richest: a serum applied over a cream cannot cross the film it leaves at the surface, and its actives are wasted. Three or four drops cover the face, neck and décolletage. In the morning, sun protection remains the final step.

Which serum should I choose for oily skin or sensitive skin?

For oily skin, a fluid serum with niacinamide or salicylic acid regulates oil production and tightens the look of pores without stripping: stripping generally triggers rebound oil production. For sensitive skin, reduce the number of actives rather than adding to them: one soothing serum focused on the skin barrier, used alone for two weeks before considering anything else. In both cases, one new product at a time.

Can a vitamin C serum and a retinol serum be used together?

Yes, but not at the same time. Vitamin C belongs to the morning, where its antioxidant action complements sun protection; retinol belongs to the evening, introduced at two applications per week to start. Layering them in a single application mostly raises the risk of irritation, with no demonstrated benefit. If your skin reacts, space out the retinol evenings before cutting back the vitamin C.