Sienna Miller's must-have cream for younger-looking skin is £13 on Amazon

Sienna Miller has always had fans admiring her skincare secrets and many were stunnned when they discovered her secret to great skin is a £13 cream from Amazon.

Beyond pricey anti-ageing gadgets and TikTok-viral bronzing serums, she attributed her flawless skin to the A313 cream, a French pharmacy-grade retinoid cream that does not require prescriptions. Originally priced at £13.88, the cream is now on a 5% discount and is marked down to £13.22.

During a conversation with , the actress retrieved her enormous blue floral-print vanity bag and remarked: "I haven't really been through, I just have been away for a month and I grabbed it, so this is authentically 'what's in my beauty bag' complete with dirty smudges."

She took out a tube of cream and revealed: "This is a really fantastic secret, it's called A313 and it's a French retinol that you can get over the counter and Alexa Chung told me about it because she's got the most amazing skin and it is described as the 'French girl secret to great skin', so we all need that."

The A313 cream contains 0.12% of the gentlest forms of vitamin A, known as retinol esters, and it aims to work on reducing fine lines, tackling pigmentation and minimising post-acne scarring whilst also treating blackheads and controlling oil production.

It boasts a thick and dense consistency that works best when applied during evening routines.

Experts also suggest beginning with gradual use by applying a small quantity in a fine layer once weekly for the initial week, progressing to twice weekly for two weeks, then three times weekly for three weeks. Irritations such as itching and flaking can occur during the initial few applications, but the brand noted this "eventually disappears once your skin becomes accustomed to it".

Sienna and Alexa Chung are not the only ones who love the A313 cream, customers have also awarded the cream an average rating of 4.3 out of five.

One customer remarked: "The best cream for hyper pigmentation, highly recommended. I saw results in a week drastically, reduced my dark spots highly recommended make sure you mix with moisturiser."

Another shared: "Love this product, it lasts a really long time and is not causing my skin to peel or break out. I do put on a light cream before this to avoid the itchy feeling retinols usually give."

A third mentioned experiencing flaking but persevered with the treatment, explaining: "For sensitive skins better try a small bit to do allergies test first. The first week I used the cream directly on my skins and it peeled, then I started to use moisturiser between layer which works fine, but less peeling. My skins turned smooth and the fine lines are less visible. During the day you need to apply the sunscreens. It's worth the money."

But a number of shoppers mentioned that the cream left the face feeling itchy as one customer said: "I tried the product for two weeks and could feel it making a difference. However, I had to stop as the persistent itching was unbearable."

A second disliked the oily texture of the cream, saying: "Really thick emulsion but I think it's too 'fatty' for me."

For lighter texture retinol creams, shoppers can try the Medik8 Crystal Retinal night serum as it comes in different strengths and is suitable for beginners, as well as experienced vitamin A users. Prices start from £45 but first-time shoppers can get 15% on their first order.

At Boots, beauty fans can try the new RoC Derm Correxion Retinol Firming Serum Stick, which is a roll-on stick for face and body and it is available to purchase at £39.99.

Sienna also added in the interview: "I do have a personal beauty philosophy which is, I think people look most beautiful without a ton of make-up, I love natural skin."

You can purchase her A313 cream on Amazon for £13.33.

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