Coffee scrubs are making a big comeback. With brands like Frank claiming that the caffeine in coffee scrubs can reduce cellulite, it sounds too good to be true. So are messy coffee scrubs worth it?
What is Cellulite?
Cellulite, also called lipodystrophy, is a change in how the fat under your skin is shaped, making it look lumpy or dimply on the surface.
The most common places to see cellulite are the bum and thighs. It’s estimated that 80-95% of women have some cellulite, so it’s not abnormal, but most people dislike how it looks and want to get rid of it.
How much cellulite you have depends on lots of factors – genetics, hormones, exercise and circulation all play a part.
The underlying changes causing cellulite are quite complex, involving water retention, poor microcirculation, inflammation, overproduction of collagen and fat storage.
How Does Caffeine Work?
Caffeine can stimulate fat cells to break down fat, and prevent fat accumulating in the fat cells as well. It can also improve circulation.
But there’s one big caveat: it could help cellulite, IF it can reach the fatty cellulite tissue located in the hypodermis, in a high enough concentration. It’s like how putting a Nurofen tablet on your head won’t help your headache – it simply can’t get to where it needs to be to act.
Can a Coffee Scrub Deliver Enough Caffeine to Work?
Actual coffee scrubs haven’t been studied at all, but there are some studies on putting caffeine on your skin in other forms.
There are lots of studies on getting caffeine to penetrate the skin, because it’s a common example used by researchers to compare penetration methods.
Caffeine penetration depends a lot on the formula of the product, as well as the amount of hair follicles in the area of skin. To get caffeine to penetrate at a rapid rate, you generally need to help it along, such as by using penetration enhancers, nanoparticles, microemulsions or ultrasound.
Coffee scrubs are usually quite simple, with coffee grounds and a plant oil as the main ingredients, so it’s safe to assume its penetration ability is on the low side.
Caffeine is also quite water soluble, and water repels fat, it tends to stay away from the fatty adipose tissue where we want it to go. Again, specialised formulations can sometimes help it get to the fat, but without it, the effect will be much lower.
Studies on Caffeine and Cellulite
With that little preamble, let’s have a look at some human/animal studies on caffeine’s effect on cellulite.
The most promising one was published in 2007 by a Brazilian research group. They found that applying a 7% caffeine gel reduced the size of womens’ thighs in the relatively large sample they looked at (~100 people).
It sounds like good news for our coffee scrub, except (there’s always an except!):
1. They used a LOT of caffeine. In the study around 15 mL of 7% caffeine gel was applied to one thigh twice a day. If we take espresso to contain 50 mg per 30 mL, this converts into 20.6 espressos per thigh, which is 618 mL of espressos – more than 2 cups.
If we go to coffee grounds used after brewing a coffee – it’s estimated that they contain 0.81% caffeine at best. To get the same amount of caffeine you’d need 2.1 kg (4.6 lbs) of coffee grounds on each thigh, twice a day – and that’s assuming all of the caffeine comes out, and all of the coffee grounds are touching your skin (probably not physically possible).
2. The thigh circumference was reduced by an average of 2.1 cm (0.8 inches). This sounds like a fair bit, but circumference is the distance around the leg, which is deceptively long. In terms of width (diameter), this converts into a measly 0.7 cm (around 1/4 inch) reduction.
3. This was also a treatment that was left on the skin and not washed off. Caffeine doesn’t absorb particularly quickly – to get 5% of the amount you applied through the skin, it takes at least a few hours, even if you’re using a really specialised formulation.
Coffee scrubs aren’t designed to be left on for too long, unless you love standing around in the shower covered in grit. And caffeine is definitely washed off and very little remains on the skin afterwards, since it’s quite water soluble, especially in warm water.
The study also looked at changes in microcirculation caused by the caffeine treatment, but didn’t find any.
- A 2015 study (open access) found that a 3.5% caffeine-containing cream improved the appearance of cellulite, but the cream contains other possibly active ingredients, the study wasn’t controlled, and was only done on 15 people.
- A 2008 study looked at the effect of a 5% caffeine gel with and without ultrasound (1 min/cm2). They found that 5% caffeine gel reduced the thickness of the fatty layer and the number of fat cells when combined with ultrasound, but not alone (ultrasound alone didn’t work either).
- A 2011 paper reports a double-blind, randomised, placebo-controlled trial where skin texture and hip/buttock/waist/abdomen measurements improved, but the product they used contained 4 active ingredients other than caffeine, including forskolin which was more active than caffeine in vitro.
Verdict on Coffee Scrubs and Cellulite
It’s really unlikely that coffee scrubs work for cellulite.
- They don’t contain enough caffeine
- They’re not left on for long enough
- They’re not formulated to help caffeine penetrate skin
But they’re pretty safe, so they’re good to use as a physical exfoliant if you don’t mind the mess and aren’t expecting your cellulite to improve!
I wouldn’t pay $30 for a bag though when there are lots of cheaper scrubs around (I personally really like the Anatomicals range!) and for a cheap DIY option, I prefer salt and sugar since they dissolve nicely down the drain without mess or the possibility of it clogging up your drains.
AM Hui, JR Jagdeo, N Brody and R Rupani, Chapter 2. Cutaneous Applications of Caffeine (open access). In Cosmeceuticals and Active Cosmetics, 3rd edn, Raja K Sivamani, Jared R. Jagdeo, Peter Elsner, and Howard I. Maibach (eds), CRC Press 2015, 19-30.
F Turati, C Pelucchi, F Marzatico, M Ferraroni, A Decarli, S Gallus, C La Vecchia and C Galeone, Efficacy of cosmetic products in cellulite reduction: systematic review and meta-analysis, J Eur Acad Dermatol Venereol 2014, 28, 1-15.
O Lupi, IJ Semenovitch, C Treu, D Bottino and E Bouskela, Evaluation of the effects of caffeine in the microcirculation and edema on thighs and buttocks using the orthogonal polarization spectral imaging and clinical parameters, J Cosmet Dermatol 2007, 6, 102-107.
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