Contract Beauty

Tag: stability testing

  • Private Label Vitamin C Serum Manufacturing: What to Decide Before You Order

    Yes, you can private label a vitamin C serum, and most contract manufacturers will take the project. But the decision that sets your price, packaging, lead time and failure rate happens before you contact anyone: which form of vitamin C you order and at what concentration. L-ascorbic acid is the most potent and the least stable; derivatives like sodium ascorbyl phosphate or ethyl ascorbic acid are gentler and far easier to keep alive on a shelf. Pick the form first, then pick the route and the factory.

    A vitamin C serum looks simple and behaves like one of the fussiest products in skincare. Unlike a lip balm or a basic lotion, the active ingredient fights you the whole way: pure vitamin C oxidises in contact with air, light and water, turning amber, smelling sour and losing its effect. That is why the upstream choices matter more here than almost anywhere else in private label beauty. This guide walks the decisions in the order a founder should actually make them.

    White label (ready-made / ready-to-go formula)
    You apply your brand to an existing, already-stabilised formula. Minimum order from a manufacturer like Moe’s Group starts at 200 units. Fastest and lowest upfront cost of the three routes — but only if a suitable vitamin C base already exists.
    Private label (custom formulation)
    Chemists develop a formula to your brief: your derivative, concentration, pH and base. Minimum order starts at 1,000 units. More brand control than white label, and more lead time, because the stability work has to finish before production can start.
    Contract manufacturing
    The broad manufacturing service a brand buys. Formulation, formula ownership, pricing and lead time are set per project, so the cost and timeline depend on what you agree rather than on the label alone.
    Chuffy, a small round anxious creature in pencil sketch, stares at a serum bottle that has turned brown.
    Chuffy opens the sample box and finds the serum has already turned amber. Vitamin C oxidised before launch day.

    What form of vitamin C are you actually ordering?

    “Vitamin C serum” is not one product. The industry uses at least five common forms, and they behave so differently that choosing one is really choosing your packaging, your pH and how hard your manufacturer has to work to keep the serum stable. Get this right and the rest of the project gets easier.

    Form Solubility Stability Typical pH Notes
    L-Ascorbic Acid (LAA) Water Moderate — needs protection 2.8–3.5 Most potent; highest irritation risk; the most formulation and packaging work.
    3-O-Ethyl Ascorbic Acid (EAA) Water and oil High 4.0–5.5 A practical choice for everyday brightening serums.
    Sodium Ascorbyl Phosphate (SAP) Water High 6.0–7.0 Gentle and stable; common in sensitive-skin formulas.
    Tetrahexyldecyl Ascorbate (THD) Oil Very high 5.5–6.5 Oil-soluble, higher cost, tolerant of standard packaging.
    Ascorbyl Glucoside (AA-2G) Water High 5.0–7.0 Slow-release; well suited to gentler formulas.

    LAA is the form most shoppers mean when they picture “vitamin C,” and it is the one that gives a serum its brightening reputation and its reputation for going off. Derivatives trade a little immediacy for a serum that survives shipping and a year on a shelf. A common commercial choice is a stabilised derivative at a workable pH; a common premium choice is LAA done carefully. Neither is wrong — but they are different manufacturing jobs, so decide before you ask for a quote. For an independent view of what finished serums on the market actually use, Wirecutter’s vitamin C serum reviews are a useful consumer-side reference.

    Chuffy holds up two bottles, one labelled white label and one labelled custom, unsure which to pick.
    Two routes, two minimum orders. Chuffy learns the choice of vitamin C form is the decision that sits above both.

    White label or custom formulation — what each means for vitamin C?

    This is where the pinned terminology matters, because the two routes carry different minimum orders and different timelines, and vitamin C exaggerates the gap between them.

    White label means you take a formula the manufacturer has already developed and stabilised, choose your packaging, and apply your label. The minimum order is 200 units. It is the fastest and lowest upfront-cost route — but it only works if the manufacturer already holds a vitamin C base with the derivative, concentration and feel you want. If you have a specific derivative or a particular concentration in mind, a stock formula may not match it.

    Private label / custom formulation means chemists build the serum to your brief. The minimum order is 1,000 units. You get more control and the formula is tailored to your positioning, but it adds lead time, and with vitamin C that extra time is not padding — it is the stability testing described below, which cannot be rushed without risking a serum that browns after launch.

    So the ordering holds: white label sits below private label, which sits below broader contract manufacturing, on upfront cost, on lead time and on how much brand control you take on. But do not translate that into a dollar figure or a number of days from the tier alone — vitamin C’s own difficulty, your packaging and your testing plan move those numbers more than the label does. If you are still weighing suppliers in general, Moe’s Group has a plain-language checklist for how to choose a private label manufacturer.

    Chuffy peers into an oven labelled 40 degrees, watching three serum bottles sweat on a shelf.
    Accelerated stability testing: 40C and 75% humidity for weeks, so the formula fails in the lab and not in the customer’s bathroom.

    What does stability testing look like, and why does it add time?

    Here is the part that goes wrong, stated plainly. Pure vitamin C oxidises — LAA converts to dehydroascorbic acid and then to diketogulonic acid — and the visible result is an amber or brown serum, a sour odor, lost brightening performance and a wave of returns. A responsible manufacturer catches that in the lab, not in your customers’ bathrooms.

    That is what stability testing is for. The standard pairing is an accelerated test at 40°C and 75% relative humidity for several weeks, run alongside a real-time test at 25°C and 60% relative humidity that continues for up to 24 months. The accelerated test is the one that adds weeks to a custom timeline, because the formula has to prove it survives heat and humidity before production is locked. Technical stability protocols along these lines are described by suppliers such as AJC Cosmolabs (competitor source, cited for technical context only; retrieved 2026-10-02).

    Stability also drives packaging. LAA formulas strongly prefer airless pumps, opaque or frosted glass, and often nitrogen-purged filling to keep oxygen out of the bottle. Derivative-based formulas are more forgiving and can tolerate standard dropper bottles, though UV-protective packaging still helps. Ask any manufacturer for a redacted certificate of analysis from a prior vitamin C run; one that will not show you stability data is telling you something.

    Chuffy stands at a crossroads signpost pointing to small batch, EU filing, and clinical LAA.
    Not every job fits one factory. Chuffy maps where to go when a manufacturer is the wrong fit.

    Where is Moe’s Group the wrong fit for a vitamin C serum?

    An honest guide has to say where a manufacturer does not fit, so here it is. Moe’s Group is a US (Chatsworth, California) contract manufacturer that is FDA registered. That is a facility status; cosmetics have no equivalent government sign-off at all (FDA cosmetics labeling guidance). It suits established and growth-stage brands ordering 200+ units white label or 1,000+ custom, working in standard serum formats with stable derivatives. It is likely the wrong fit in these cases:

    If you need… Look at instead (checked 2026-10-02)
    Under 200 units — a proof-of-concept or launch test AJC Cosmolabs and other low-MOQ US labs; confirm their current minimum directly, as MOQs change.
    EU or UK launch with CPNP/PIF filing bundled into manufacturing An EU-based manufacturer such as DEL’LA SOFT (Turkey); verify current MOQ and included regulatory docs on their own page.
    Asia-first supply chain or direct China sourcing China OEMs such as Zerun Cosmetic or Lezha Beauty; check their own current terms.
    Clinical-grade high-percentage LAA in nitrogen-flushed airless packs Verify any manufacturer’s filling line handles high-LAA formats first; specialist labs such as SkinCraft Lab may suit. Do not assume any single factory, including Moe’s, runs this format — ask.

    One piece of market context worth knowing: according to Wirecutter, the patent on SkinCeuticals’ original CE Ferulic formula (roughly 10% LAA with 1% ferulic acid and 1% vitamin E) expired in 2025, so any GMP lab can now reproduce that combination. If that is the serum you want, it is effectively a commodity formula today — price-shop it widely rather than paying a premium for the recipe. For scale context, the US vitamin C serum market is estimated in the low billions of dollars, with stabilised derivatives making up a growing share of new launches (IndexBox, 2026).

    What should you ask a manufacturer before you sign?

    Walk in with these questions and you will sort a capable partner from a hopeful one quickly:

    • Which vitamin C form and concentration is in your stock serum, and can you formulate the one I want?
    • What pH does the finished formula hold, and how do you keep it there?
    • Does your filling line offer airless or nitrogen-purged filling for LAA formats?
    • Can you share a redacted CoA and stability data from a prior vitamin C production run?
    • White label or custom for my case — and what minimum order and timeline does each carry for this serum specifically?

    The answers tell you whether the factory treats vitamin C as a routine job or a serious one. It should be the latter.

    Frequently asked questions

    Can you private label a vitamin C serum? Yes. You can apply your brand to an existing stabilised formula (white label, from 200 units) or have one developed to your brief (custom formulation, from 1,000 units). The form of vitamin C you choose matters more than the route.

    Which vitamin C form is most stable? Derivatives such as tetrahexyldecyl ascorbate, sodium ascorbyl phosphate and ethyl ascorbic acid are considerably more stable than pure L-ascorbic acid, which is the most potent but the most prone to oxidising.

    What concentration is typical? Leave-on serums commonly sit in the 5–20% range, with 10–15% widely cited as a practical sweet spot. The right number depends on the form and your audience.

    Why do vitamin C serums turn brown? That amber or brown color is oxidation — the vitamin C degrading. Low pH, antioxidant co-ingredients like ferulic acid and vitamin E, and air-tight opaque packaging all slow it down.

    What minimum order should I expect? From a manufacturer like Moe’s Group, 200 units for a ready-made white-label formula and 1,000 units for a custom formulation. Other manufacturers set their own minimums; confirm each directly.

    If you have decided on your form, concentration and route and want to talk specifics with a US manufacturer, Moe’s Group takes project enquiries through its product inquiry form.

    Chuffy proudly holds an airless pump bottle of clear serum, finally not brown, with a small relieved smile.
    Clear, stable, and still clear a year later. Chuffy got there by deciding the hard things before placing the order.

  • What Is Cosmetic Stability Testing — and Does Your Manufacturer Handle It?

    Cosmetic stability testing checks whether a formula stays safe, effective and consistent from the day it is filled through the end of its shelf life. For a custom (private label) formula it usually runs alongside or after prototype development and adds weeks to your launch timeline. For an existing white label formula the testing has already been done — you ask your manufacturer for the documentation rather than commissioning it yourself.

    If you are launching a beauty brand, “stability testing” is one of those phrases that sits quietly on a quote and then turns out to control your launch date. It is not a single test. It is a set of studies that answer one question: will this product still be the same product in twelve or twenty-four months, sitting on a warm shelf, opened and closed by a customer? Here is what it actually involves, whether the law requires it, and who does it — your contract manufacturer, or an independent lab.

    Chuffy, a small round anxious sketched creature, stares at a freshly filled jar of cream and asks whether it will still be fine next year.
    Chuffy has a filled product. What he does not have yet is proof it will survive a year on a shelf.

    What does cosmetic stability testing actually check?

    Stability testing exposes your formula to conditions harsher than a normal shelf and watches for change. The reference protocol most labs follow is built on ICH-style guidelines adapted for cosmetics, and it typically covers:

    • Physical stability — does the color, odor, texture or viscosity drift? Does an emulsion separate?
    • Chemical stability — do the active ingredients degrade, and does the pH move outside its safe range?
    • Microbial stability & preservative efficacy (PET) — can the preservative system still fend off contamination after the product has aged?
    • Package compatibility — does the formula react with, leach into, or corrode its container?
    • Stress conditions — freeze-thaw cycling, light exposure (photostability) and heat, to model shipping and storage abuse.

    Two study types run in parallel. Real-time studies keep samples at normal conditions for the full claimed shelf life — commonly 12 to 24 months. Accelerated studies hold samples at an elevated temperature and humidity (a widely used setpoint is 40°C / 75% relative humidity) to force change faster and give interim data in roughly 8 to 12 weeks. Accelerated data lets you move; real-time data confirms the shelf-life claim you print on the label.

    Chuffy peers into a lab stability chamber where jars sit under a thermometer, looking nervous about the heat.
    The accelerated chamber runs hot on purpose. It is trying to break the formula before a customer does.

    Is cosmetic stability testing legally required?

    Not as a specific, named protocol. Under the Modernization of Cosmetics Regulation Act (MoCRA), the responsible person for a cosmetic must ensure and keep records supporting adequate substantiation of safety. MoCRA does not mandate a particular stability test or time point. The FDA’s own guidance on product testing treats testing as the manufacturer’s responsibility and points toward independent labs for objectivity.

    So stability testing is best practice that safety substantiation strongly implies, rather than a line-item legal command for most cosmetics. Two caveats matter. First, MoCRA’s Good Manufacturing Practice rule was originally due by the end of 2025 and, as of early 2026, was still listed as a long-term action with no proposed date — check the current status before you rely on it. Second, OTC drug products — sunscreens, acne treatments, anti-dandruff shampoos — are a different world. They fall under drug GMP (21 CFR Part 211), which carries its own stability obligations. If your product makes a drug claim, the answer to “is it required?” changes to yes.

    Note also that Moe’s Group is FDA registered — a facility registration. There is no equivalent FDA sign-off for a finished cosmetic, so treat any supplier who implies one with caution.

    Chuffy holds up a thick MoCRA rulebook and looks relieved that it does not name a single test he must run.
    The law asks for substantiated safety. It does not hand Chuffy a checklist — which is its own kind of stressful.

    Who does the testing — your manufacturer or an independent lab?

    Both routes are legitimate, and the right one depends on your situation. A full-service contract manufacturer that develops your formula will usually build stability testing into development. Moe’s Group describes exactly this in its guide to skincare formulation from concept to consumer shelf: each prototype “undergoes rigorous performance and stability testing under varied conditions” to confirm the formula “maintains its integrity, color, and consistency across its shelf life,” covering microbial stability, temperature resistance and packaging compatibility. That testing sits inside its ISO 22716 (cosmetics GMP) certified quality system.

    An independent lab is the better fit in several common cases, and it is worth being honest about them:

    You already have a manufacturer and only need testing
    Microchem Laboratory is ISO 17025-accredited, FDA-registered, and explicitly markets real-time, accelerated, freeze-thaw, photostability and preservative-efficacy testing to small and mid-size personal care companies. A contract manufacturer that did not develop your formula is not the place to send a standalone testing request.
    You want third-party validation specifically
    If a retailer, investor or insurer wants an independent certificate, you need an external lab no matter who made the product. Eurofins is the large-scale, multi-test option here; expect an enterprise orientation and a quote-based process rather than a published price.
    You are pre-revenue and price-shopping one SKU
    A marketplace such as AJ Cosmo Labs connects indie founders with vetted stability labs; its published material puts a full 12-month real-time study with accelerated data at roughly $1,500–$4,500 per SKU (published June 2026). That is a sensible first step before committing to any manufacturing minimum.

    Where Moe’s Group is the wrong fit: it does not offer standalone stability testing for a formula it did not develop. If testing is genuinely all you need, use an independent lab. Moe’s is the right conversation when you want a factory to formulate, fill, label and test as one project — not when you want to buy a single test off the shelf.

    Chuffy stands at a fork in the road between a factory and an independent testing lab, holding a jar and looking undecided.
    Manufacturer or independent lab? The honest answer is: it depends on what you actually need done.

    What is different for custom (private label) versus stock (white label) formulas?

    This is where stability testing quietly changes your budget and timeline, and it maps directly onto the two routes a contract manufacturer offers.

    White label (ready-made / existing formula)
    Ready-to-go formula with a 200-unit minimum at Moe’s Group. Because the formula already exists, its stability testing has already been done. Your job is to ask for the shelf-life documentation and confirm what the baseline formula was tested against. You inherit the data; you do not pay for a new study or wait for one. This is the faster, lower-commitment route on stability as well as on price.
    Private label (custom formulation)
    A bespoke formula with a 1,000-unit minimum. A new formula means a new study. Stability testing runs during or after prototype development, before scale-up — accelerated data in roughly 8 to 12 weeks, real-time confirmation over 12 to 24 months. Build that time into your launch plan; a custom formula is not truly market-ready until its stability picture is in.
    Contract manufacturing (the service itself)
    The umbrella term for a factory making a product to a brand’s specification. Where testing, ownership and lead time land depends on the specific project rather than on the label “contract manufacturing” alone.

    The practical takeaway: if speed matters more than a signature formula, a tested white label product removes the stability wait entirely. If your point of difference is the formula, treat stability testing as a scheduled phase, not a surprise.

    Frequently asked questions

    How long does cosmetic stability testing take?

    Accelerated studies give interim data in about 8 to 12 weeks. Real-time studies run for the full claimed shelf life — commonly 12 to 24 months — and are what ultimately back up the expiry or period-after-opening you print.

    How much does it cost?

    It varies by lab, scope and number of SKUs. As one public reference point, AJ Cosmo Labs lists roughly $1,500–$4,500 per SKU for a full 12-month real-time study with accelerated data (June 2026). Labs like Eurofins quote per project rather than publishing a price.

    Does my contract manufacturer include stability testing?

    A full-service manufacturer that develops your formula usually does — ask for it in writing and ask for the resulting documentation. If you already have a formula and a manufacturer, a manufacturer will typically not test a formula it did not develop; use an independent lab instead. When in doubt, ask the factory directly what their process covers before you sign.

    Chuffy grins and holds up a stability certificate at last, standing beside a calendar showing that six months have passed since he thought he was ready to launch.
    Chuffy’s formula passed — six months after he was sure he was ready to launch. Stability testing is a phase to plan for, not a surprise to trip over.