Put the brakes on dark spot formation, and prevent uneven and dull skin with these hot weather must-haves. It's not only high-protection sunscreens that should be whipped out when the going gets blazing hot - it's also brightening treatments that carry out the damage control and repair on dull-looking skin.

While different products may have different mechanisms for achieving a brightening effect, Dr Kok Wai Leong, a dermatologist at DS Skin & Wellness Clinic, says most generally work to even out areas of hyperpigmentation.

"These formulas either block melanin production and aggregation, decrease activity of melanocytes - which are the cells that produce melanin - or interfere with signals between skin cells and pigment cells," he says.

Some products function by boosting skin renewal, removing the outer layer of dead skin cells to bring about a fresher, brighter and more even complexion. In doing so, they also create a smoother skin surface for light to bounce off.

Dr Hong Foo, founder of Bespoke Aesthetics, says that some key ingredients worth looking out for when choosing a brightening product are niacinamide, exfoliating enzymes and acids, arbutin and liquorice.

Tranexamic acid and retinoic acid are even more potent, especially in oral form, he says, but are usually not available in off-the-shelf products in pure or high concentrations.

There's also vitamin C, an ingredient that's almost de rigueur when it comes to brightening skincare.

Dr Kok says: "Vitamin C is a key component in many skin-brightening products because it not only blocks melanin production, but is also an antioxidant that protects against the harmful effects of ultraviolet light exposure.

"However, its efficacy depends on factors like pH, oxidation, and stability of the formulation. For that reason, it is usually combined with complementing ingredients, such as ferulic acid, zinc and tyrosine, to boost absorption and stability," he adds.

Dr Hong says that because medical grade vitamin C is often unstable, it has to be packaged in an opaque bottle. (Remember this when buying skincare with vitamin C as a key element)

"Vitamin C eventually oxidises and loses its potency after contact with light, heat and air. That's why they generally have an expiry date of not more than one year," he says.

He adds that the ingredient's efficacy is dependent more on the type of vitamin C rather than its dosage or concentration.

"For example, L-ascorbic acid is an excellent source of vitamin C, but it's extremely unstable. That is why products sometimes use alternative forms of vitamin C in order to balance stability and effectiveness," explains Dr Hong.

Although the constant improvements to brightening skincare means that many of them now can be used even on sensitive skin, Dr Kok cautions that some compounds may still cause skin irritation or sensitivity when exposed to sunlight after application.

"If you have sensitive or inflamed skin, products containing retinoids or retinol will cause the superficial part of the skin to peel. It's also best to avoid exfoliants like alpha or beta hydroxy acids, as overuse may further damage the skin barrier," he warns.

For a list of brightening skincare products, read on.

C-Firma Fresh Day Serum, $110, Drunk Elephant

Its vitamin C comes in the form of 15 per cent L-ascorbic acid powder, which is mixed with the serum base before first use.

The serum is also packed with antioxidants, nutrients and fruit enzymes that not only brighten, but firm skin.

Even Better Clinical Radical Dark Spot Corrector + Interruptor, $150, Clinique

Using a proprietary brightening molecule and vitamin C, it promises to visibly lighten dark spots, age spots and acne marks in 12 weeks.

Salicylic acid works to slough off dead skin, while green tea extract quells irritation to prevent hyperpigmentation.

Floral Recovery Calming Mask, $105, Fresh

Drawing on the powers of floral extracts including passionflower, cherry blossom and peony, this soothing treatment works overnight to reduce signs of sensitivity like redness, uneven skin tone and rough texture.

7-Day Brightening Rescue Mask, $72.80, Glowfully

Designed for all kinds of skin emergencies, this repairing mask immediately calms, hydrates and clarifies splotchy, irritated skin. Tranexamic acid, niacinamide and liquorice restore luminosity, while cucumber and camomile soothe inflammation.

Vinoperfect Radiance Serum Complexion Correcting, $45, Caudalie

One bottle of this cult product sells every 30 seconds worldwide. It's said to tackle all kinds of dark spots that occur on various skin tones.

The hero ingredient here is an antioxidant found in vine sap that's reportedly more effective than even kojic acid and ascorbic acid.

Herb Bouquet Concentrate, $93, Belif

A lightweight and non-greasy serum that delivers the benefits of 15 herbs, including rosemary, thyme, rose oil, almond oil and dandelion.

Plus, it has niacinamide to firm skin and minimise pores, and vitamin C to even out skin tone.

V7 Brightening Mask, $32, Dr Jart+

Comprising 40 per cent moisturising agents, this microfibre sheet mask is infused with a complex of seven vitamins (including A, C and E) and soothing calamine to perk up dull skin.

With consistent use, it also helps to brighten skin's undertone.

Hope In A Jar Instant Glow Peeling Mousse, $55, Philosophy

A minute is all it takes to get glowing, even-toned skin with this exfoliator, which rolls away impurities and debris using an enzyme complex.

Vitamin B5 helps retain moisture so skin won't feel dry, tight and inflamed.

ALSO READ: 10 soothing spot treatments that calm and treat breakouts overnight

This article was first published in Her World Online.