How Long Should You Give a Skin Cream To Work?

Adverts for beauty products make big claims. Well when you read them literally in the way a lawyer would read a contract they often make no claims at all, but they are certainly designed to give you the impression that they are going to do a lot for you. I am not a lawyer and the fine print leaves me cold. The fact is that you are being led to believe something and what you are being led to believe is pretty clear.

And the reality is that some brands do live up to the promises they make while others oversell. And in fairness, we all have subtly different physiology and what works for one person may well be useless for another. Often the only way to sort out the sheep from the goats is to buy it and give it a try.

But how long should you give something before you decide whether or not it has done what you paid your money for or not?

This is one of those questions to which there is no right or wrong answer, but it is nonetheless one that I am pretty sure I know the answer to.

If you can’t detect a noticeable benefit in a week, I think you are justified in deciding that the promise will not be fulfilled and you are justified in taking your custom elsewhere.

Now it is certainly the case that if you want to prove that something works in a clinical trial, it will take a lot longer to do it. Clinical trials on pharmaceutical actives for conditions like acne sometimes run for six months. And there are good reasons why this should be the case. If you use a product for a week and it works that does not prove anything scientifically. Scientists want to generate enough data to carry out a statistical analysis to give themselves confidence that any observations are significant. And quite right too.

But as a consumer you don’t have to prove anything to anyone else, but you do have to prove it to yourself. If something is going to take multiple weeks before you notice it, the effect is going to be pretty small. And you will start to get taken in by the sunk cost fallacy. Having put that much effort in, the temptation to think you must have done some good is great.

I have been deliberately vague about what benefit I am talking about here, because I really think this applies across most product types. A moisturiser should moisturise your skin noticeably within a week. An anti-wrinkle cream should be reducing your wrinkles within a week. If it doesn’t do anything you can notice in that time, multiplying that effect by twelve is still a very small effect. You should be paying for something that you can see reasonably quickly.

There is plenty of choice out there. If what you have tried doesn’t work, try something else. And try something different. There are more choices available now than at any time in history so there is no need to settle for poor performance.


From the UK, Colin Sanders has been a formulator of cosmetic and topical pharmaceuticals for 27 years. Over that time he has formulated nearly every category of product including shampoos, cosmetic skin creams, pharmaceutical skin creams, face masks, lip balms and so on. He has been an active member of the Society of Cosmetic Scientists since 1985 and in 1999 organised the first of the Formulate shows. His degree is in environmental science and he continues to take a keen interest in the impact of human activities on the planet. He regards himself as an environmental activist and all round green. When not in the lab, he writes a blog, Colin’s Beauty Pages with the intention of entertaining and hopefully informing users of cosmetic and personal care products with some insider insights, a bit of science and his own opinions.

  • Anonymous

    Colin, very interesting as this is something I have been thinking about recently. I wonder though why 1 week? I’ve been reading alot of the in house studies done by some of the ‘actives’ companies and most of them seem to look at effects after 2 months or so. For instance this study about Matrixyl (Palmitoyl Oligopeptide (and) Palmitoyl Tetrapeptide-3) ( reports increased skin thickness in 4 weeks, Decrease in deep and intermediate wrinkles, improve skin tone and elasticity 56 days, but increased collagen synthesis in vitro in just 72 hours. Since manufacturers are giving results in 1-2 month time scales why do you think it should take a week? Perhaps it that something recognizable only to the user would occur in 1 week but measurable results would be 1-2 months. Seems a week would be plenty for moisturizing but for wrinkle reduction it seems too fast to me. Just wondered what your take on that was. thanks.

    • beautyscientist

      If you continue getting improvements after a week that isn’t a problem. But if it takes a couple of months before you even notice anything, how big an effect can it be having?

      • Philippe Papadimitriou

        Physiology is fast, but visible results do not come that fast.

        If one company for example measures an average -12% of wrinkles lenght in a month on a panel of 30 volunteers (not even double blind), how do one expect a consumer to perceive a 2-5% diminution after a week?

        The efficacy of “whitening” ingredients is also depending on the delay of melanin turnover. Melanin is produced in permanence (roughly said). If you limit its synthesis with the presence of an ingredient, you still need more than 7 days to visibly percieve any difference (as a portion of melanin will have disappeared and not be replaced).

        I personally would recommend at least 3-4 weeks.

        I know of no company that will give free samples for a week of use. So at least finish the product you have paid for, unless you prefer to visit a dermatologist to have a clinical quotation on the parameter of your choice (wrinkles, nourrishing, etc.) or even get silicone cutaneous imprints or pass a fringes projection. If methods such as these have been created it is because self-evaluation is not enough, particularly after a short period of time.

        Who can say she/he has felt a 7.4% improvement of her/his trans-epidermal water loss (TEWL)?

        I regret that comsetics are sold as being junk science. They are far more than that.

        NB: Moisturization happens much faster, yes.

  • Ann Wooledge

    Before formulating my own creams, I went through a LOT of expensive products over the course of many years and since none of it worked, I can just personally tell you in a nonscientific way, that I could tell a difference within 24 hours. Some of this may just be plumping of the skin and the immediate moisture received, but these are some of the most basic properties that most of us are looking for. As far as actual wrinkle reduction, then that would take a few months – or I think most customers will give it that much time as long as the product doesn’t cause any other reactions such as acne, clogged pores of irritation. We do have a consistent response from our customers that they can tell almost an immediate “dewy” feel to their skin after one day. And we get a lot of these, so I can say that the are seeing a response within 24 hours. I haven’t kept count, but know it’s a high percentage, of how many repeat customers we have indicating that it worked at some level. Without doing a “clinical” trial, this documentation would give any company a way of seeing how their product(s) are received.

    • Philippe Papadimitriou

      Moisturization happens fast. It also somehow is the main objective of all cosmetic products.
      But do not get confused between perception and measures.

      We had done an TEWL test on a product where we got near 100% satisfaction for the nourrishing parameter (questionnaire – 25 subjects), but only got a very poor measurable effect.

  • Sarah

    I always understood that treatment for melasma takes months, too. At least that’s why I’m being so patient with my retinol. I can’t tolerate a high concentration because I have rosacea, but after months and months of use, I do see changes in the melasma patches, they’re just slow. Perhaps I’m too optimistic…

  • Carolhardin

    Yes, I do agree with you. The effect of any cosmetic can be noticed with in a week. I really appreciate your point about to prove the effectiveness of the cream. I do agree that we need to prove it for our self only.

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