Serum bottles: choosing size, glass and dispenser

Serum packaging has a harder job than fragrance packaging. The product is usually more expensive per millilitre, often light sensitive, and dispensed in small controlled doses. The bottle has to protect the formula and meter it accurately.

This guide covers the three decisions that matter: size, glass, and how the product comes out.

Standard sizes

Serum sizes cluster tightly compared with fragrance.

15 ml, 30 ml and 50 ml

15 ml is the sampling and travel size, and increasingly a full retail size for high concentration actives.

30 ml is the volume most of the category sits at. It works out to roughly a two month supply at typical use, which suits a repurchase cycle.

50 ml appears in body serums and hair serums where dosage per application is larger.

100 ml and above belongs to face oils and hair treatments rather than concentrated serums.

Ounce equivalents matter for export. 15 ml is 0.5 fl oz, 30 ml is 1 fl oz and 50 ml is 1.7 fl oz. A full conversion table is in our ml to oz conversion chart.

Clear, amber or opaque

Glass colour is a formulation decision before it is a design decision.

Amber glass and light sensitive actives

Vitamin C, retinol and many botanical extracts degrade under ultraviolet light. Amber glass blocks a substantial part of that spectrum and is the default for these formulas. The colour comes from the melt, so it cannot scratch off.

Frosted or coated clear glass reduces visible light transmission but offers much less ultraviolet protection than amber. If you choose it for a light sensitive formula, the secondary carton has to do the work instead.

Clear glass shows the product, which is an advantage when colour is part of the appeal. It suits stable formulas and products sold in an outer box.

Opaque coated glass gives full design freedom on the exterior and good light protection, at the cost of the customer being unable to see the fill level.

Glass grades and how tint varies between them are covered in our glass perfume bottles guide, and the same grades apply to serum bodies.

Dropper or pump

The dispenser choice changes both dosing accuracy and how much product is exposed to air.

Glass pipette droppers

A glass pipette dropper gives visible, controllable dosing and reads as a premium cue in skincare. It also lets air into the bottle on every use, which shortens the life of oxidation prone formulas. Bulb material matters here; a nitrile bulb resists oils better than a natural rubber one.

Treatment and airless pumps

A treatment pump delivers a fixed dose and keeps the bottle closed between uses. Dosing consistency is better and contamination risk is lower, but the customer cannot see how much they are dispensing.

An airless pump keeps the product in a sealed pouch or behind a follower plate so it never contacts air. This is the right choice for unstable actives and the most expensive of the three.

For the neck finishes these dispensers use, and which pump fits which body, see our neck finish and pump compatibility guide. Product ranges are on the serum bottles page.

How to open a serum pump bottle

Most treatment pumps ship locked so they do not discharge during transit.

Unlocking and priming

Turn the pump head anticlockwise while holding the bottle. The head rises when the lock releases. Some designs require the head to be pressed down first, then turned.

Once unlocked, the pump needs priming. Press it six to ten times until the tube fills and product appears. A new pump never dispenses on the first press.

If the head still will not move, look for a transit clip under the head or a collar that has to be lifted. If dried product has sealed the join, wipe it with a cloth dampened with warm water and try again.

Do not lever the head off. The stem breaks before the lock gives.

Filling considerations

Serums are more sensitive to packaging interaction than fragrance, so the compatibility test is not optional.

Compatibility testing

Fill a sample, seal it, and store it at room temperature and at elevated temperature. Check colour, clarity, scent and viscosity at intervals over several weeks. Watch the dropper bulb specifically; incompatible rubber swells or hardens and both failures ruin the dose.

Check the dip tube reaches the base. Serum is expensive, and product stranded at the bottom generates complaints out of proportion to the amount involved.

Leave headroom. Filling to the brim leaves no room for the dropper stem or for thermal expansion.

Regulatory labelling in the EU

If you sell into the European Union, cosmetic products fall under Regulation (EC) No 1223/2009. Among other things it requires the responsible person's name and address, the nominal content, a batch number, the list of ingredients in INCI nomenclature, and either a durability date or the period after opening symbol.

That has a packaging consequence. Small serum bottles rarely have enough surface for a full INCI list, so the information moves onto the outer carton or a peel back label. Decide this before you approve the label area on the bottle, not after.

Building a serum range

If you already sell fragrance and are extending into skincare, the components mostly transfer. The glass grades, neck standards and cap families are shared. What changes is the dispenser and the light protection requirement.

Jars for creams and balms are on the cream jars page, and lotion pumps for larger formats on the lotion pump page.

To specify a serum bottle, dropper and cap combination for a particular formula, get in touch through the contact page.