Pregnancy can be a trying time: you can’t tell whether you’re nauseous or hungry, your body is working at close to the sustainable limit of human endurance, your organs are rearranging to make space for a growing alien.

There are myriad indignities: nosebleeds, swelling feet, back pain and, if you’re unlucky, ceaseless vomiting that goes “full Tarantino”.

That’s all without having to contend with a sudden onslaught of luminous pregnant influencers, surfaced by omniscient algorithms, who lovingly massage various creams into their gravid bellies. Targeted advertising for pregnancy-specific skincare begins to stalk you around the internet, offering products with asinine names: “mummy’s tummy”, “bump love”, “belly butter”.

“There’s a lot to think about when you’re expecting – but stretch marks don’t have to be one of them,” proclaims the advertising copy for a “deluxe set” of organic belly products (RRP $75).

For $68, another Australian skincare brand sells a “firming oil” that contains as its primary ingredient sunflower oil, of frying pan fame – not exactly the cooking expectant mothers might have in mind.

Such pregnancy lotions variously claim to prevent stretch marks, boost skin elasticity, reduce redness and soften skin – but do the products actually deliver?

Can oils or lotions prevent stretch marks?

There are three main factors that determine someone’s likelihood of developing stretch marks in pregnancy, according to Dr Cara McDonald, dermatologist and director of Complete Skin Specialists – genetics, younger age and rate of weight gain.

“We don’t know exactly how much is genetically determined versus other factors, but certainly a family history is significant,” McDonald says.

The skin is composed of three layers: the epidermis, the uppermost layer of skin cells; the dermis, comprised of “collagen and elastin fibres that give stretch and integrity”, and the hypodermis, also known as subcutaneous tissue.

When the skin stretches too quickly, the dermis tears “rather than being able to remodel fast enough to grow and stretch”, McDonald says.

Because stretch marks occur deep under the surface of the skin, any “surface application is not going to do a whole lot”, says Dr Anita Lasocki, dermatologist and practice principal at South Road Dermatology.

“What you do to the surface of the skin will certainly keep your skin soft,” Lasocki says, but she notes there is no evidence that creams or oils work at all to prevent stretch marks.

There is little point spending money on expensive creams during pregnancy, she says, adding that many products prey on women at a vulnerable time. “Keep your skin soft with whatever moisturiser agrees with you … it doesn’t have to be expensive.”

McDonald adds that when you use any moisturiser, what you’re really doing is hydrating the epidermis. “You’re adding hydration for your skin barrier, which is like the mortar between your skin cells. That has no relevance necessarily to the underlying dermis, which is where the actual stretch mark occurs.”

Reducing the appearance of stretch marks

“When stretch marks are fresh, they’re often very purple or vividly red. The redness naturally over time will fade,” Lasocki says.

If someone is postpartum and wants to reduce the redness of their stretch marks, vascular laser is an option. “That’s very safe, and makes them look less red,” Lasocki says, though she notes that laser is not necessary “for the majority of patients as time is usually their best friend – within 12 months most tend to fade to silvery lines.”

Vascular laser is thought to stimulate collagen production, which can improve the appearance of early stretch marks, as do topical retinoids. However, retinoids should be avoided during pregnancy, because they are derived from vitamin A, which has been linked to birth defects when taken orally.

For stretch marks that are already silvery and pale, other laser treatments exist that claim to “work on the principle of causing some trauma to the skin to try and stimulate new collagen,” Lasocki says. “But they’re never ever going to erase the stretch mark – they’re going to maybe soften the appearance. Ultimately a faint silvery line is what you’re going to be left with.”

Safe skincare in pregnancy

Everyone’s skin changes in different ways during pregnancy, McDonald says. Some women report a “pregnancy glow”, the result of increased oil production due to hormone changes. “The problem is, if you get increased oil production and you’re acne prone, you tend to get acne and break out,” McDonald says. Similarly, pregnancy can exacerbate existing skin conditions such as rosacea and psoriasis.

Hormone changes during pregnancy can also increase pigmentation, resulting in darker areolas, melasma (brown patches on the face) or a line running down the midline of the abdomen, known as the linea nigra.

Lasocki emphasises the importance of staying on top of treatments for pre-existing conditions, and also regular skin checks. “If women are worried about moles that are darkening, they should still get them checked in pregnancy,” she says.

Experts recommend avoiding retinoids out of an abundance of caution, as well as prescription actives such as hydroquinone and fading creams.

Salicylic acid – which aspirin breaks down to in the body – is also generally avoided, McDonald says, though she says “in small amounts it’s probably no issue”.

“Most over-the-counter things are OK”, Lasocki says, noting that “some women find their skin is more reactive in pregnancy”.

She recommends “a simple moisturiser to maintain skin integrity”, with key ingredients being glycerin – which prevents moisture loss – and ceramides, which are good for the skin barrier.

“Something sensitive, fragrance-free, inexpensive … is about as exciting as it needs to get.”

• Donna Lu is an assistant editor, climate, environment and science at Guardian Australia

• Antiviral is a fortnightly column that interrogates the evidence behind the health headlines and factchecks popular wellness claims