Sienna Miller' £16 French retinol cream gives her great skin and you can get it on Amazon

Sienna Miller has delighted fans by sharing the skincare products behind her glowing complexion. Other than expensive anti-ageing tool and TikTok-viral creams, she also credits her flawless skin to a £16 cream that you can get from Amazon.

In a chat with Harper's Bazaar, she took out her gigantic blue floral-print beauty bag and said: "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 pulled out a tube of cream and explained: "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 mildest forms of vitamin A, called retinol esters, and it aims to work on diminishing fine lines, anti-pigmentation and reducing post-acne scarring as well as treating blackheads and regulating oil control.

It has a thick, greasy texture that is best to use at night. It is also recommended to start with a gradual application by taking a small amount and spreading it in a thin layer, once a week for the first week, then twice a week for two weeks and three times a week for three weeks.

Irritations such as itching and flaking can happen during the first few applications but the brand mentioned this "eventualy goes away once your skin gets used to it". Trusted by Alexa Chung and Sienna, shoppers have given the cream an average score of 4.3 out of five.

One said: "If you can bear the itch, it works miracles." And a second added: "I have used for the whole winter and can see results. Definitely a good product!"

Another said she had flaking but trusted the process and explained: "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."

Sienna said: "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 get her A313 cream on Amazon for £15.95.

She also listened to her 11-year-old daughter's recommendation and uses Glow Recipe's bronzing Watermelon Glow Niacinamide Hue Drops, a makeup-skincare hybrid that everyone's been talking about. It hydrates your skin and has a luxurious bronzy tint.