Today, when I woke up, I made myself a cup of warm lemon water. After lunch I dropped a Berocca into a glass to power me through the afternoon haze. Running errands I considered treating myself to a Coke but opted instead for an expensive, vegetable-tasting water.

H2O classic may be a prerequisite to all known forms of life, but countless brands insist they have found ways to “improve” water. From a business standpoint, it’s working. Industry researchers IbisWorld estimate Australia’s “functional beverage” industry is worth $445.6m; and as people become more health conscious, the growth of the sector is outpacing the economy overall.

Like my day, the quest to boost water began by adding citrus. As early as the 12th century, the physician to Sultan Saladin was cataloging their qualities in a “Treatise of the Dietetic Properties of the Lemon”. By the 18th century, the Royal navy was pouring lemon and lime juice down sailors’ throats to prevent scurvy. In the midst of the US Civil War, one concerned citizen even wrote into the New York Times to suggest soldiers be provided “a few lemons every day” because “raw lemon juice will prove of immensely more benefit to sufferers from that indescribably dreadful thirst than buckets of water”.

Not quite as storied, my old pal Berocca first appeared in the 1960s, followed by a brightly coloured alphabet of vitamin effervescents, powder sachets and slickly branded bottled waters.

‘Not many people are actually vitamin deficient’

Vitamin water may have made sense for nutrient-deprived 18th century seamen, but there is little scientific love for these products now. “There is nothing you can get from Berocca that’s not available in a normal diet,” points out Dr Shea Wilcox, a general practitioner working in Melbourne. Berocca agrees with this sentiment, stating more than once in its FAQ that “vitamin and mineral supplements are not a substitute for a balanced diet”.

“If someone has a vitamin deficiency of some degree, we don’t recommend they take Berocca,” Wilcox says. “It’s never offered as a treatment for anything.” He suggests that our enthusiasm for these products outpaces our need as huge improvements in the general population’s diet has meant that “not many people are actually vitamin deficient”.

If you do lack a specific micronutrient, the recommended treatment is to adjust your diet or top up with a doctor-directed supplement for a set period of time, or until you’ve returned to a normal level. Endlessly guzzling enriched water isn’t the way to get there.

‘Your body is fantastic at detoxifying’

Lemons might have sparked our interest in vitamin waters, but they also flow into the looming conversation around “detoxification” and how specialised drinks can assist with it. Anyone who has ever been on YouTube, read a “my day on a plate” article, or listened to professionally good looking people claim their beauty is cultivated, not gifted, has heard of lemon water’s celebrated “cleansing” properties. Our terror over grimy insides has also seen liquid charcoal, milk thistle, magnesium, zinc and others join the growing fight against toxins.

But, as Wilcox puts it, “Your body is fantastic at detoxifying itself without any outside assistance … it’s part and parcel of being a successful organism.” It doesn’t need a dose of expensive cleansing products to do so, since it has “an entire pathway to make sure there are no toxins”.

This long standing and widely available advice hasn’t dented the eternal dream that water, if handled correctly, could be a mythical source of loveliness and vitality.

‘It’s a big myth that drinking water can help with improving skin’

Lately, while feeling dull, I’ve also found myself online, surfing the rising ocean of “beauty waters” that promise to make me more luminous, refreshed and, well, beautiful.

The search for the fountain of youth reaches back to Alexander the Great. Except now rather than a magical spring, we reach for water containing products such as roses, crystals and exotic fruits alongside the less whimsical-sounding collagen, amino acid, silica and selenium.

These good looking, although usually pricey, products promise to improve skin elasticity, complexion, and offer a pleasing glow. While the branding is better, they exist in the same nutritional space as vitamin waters. Some may contain ingredients that are in theory good for you, but they aren’t delivered in a way that is really beneficial.

Echoing Wilcox’s advice, dermal therapist Yadira Galarza Cauchi recommends only taking “supplements under the guidance of a dietician or medical professional”. Adding that “excess amounts of water soluble vitamins are naturally excreted when over-consumed” – ie: you pee the expensive stuff out.

She’s generally weary of simplistic associations between water and skincare, positing: “It’s a big myth in this industry that drinking water can help with improving skin qualities such as skin hydration.”

In reality “topical skin care is required for this … in conjunction with a balanced diet.”

Alkalinity and extra oxygen?

While beauty and vitamin waters stand pretty close together, some brands have broken away, with products focused on tinkering with the molecular structure of water itself. There are waters that claim to have increased the amount of oxygen and hydrogen. With water already being well reviewed, you can kind of understand the impulse to add “more of the good stuff”, but here too promises that hacking the classic recipe will improve hydration, post-exercise recovery and reduce inflammation have been dismissed by doctors and failed to stand up in physiological testing.

Fans (or marketers) of alkaline waters are even more ambitious in their effort to upgrade water, claiming that by pushing pH levels up from tap water’s natural 7 to 8 or 9 they can regulate the body’s own pH levels. This difference can allegedly slow ageing, prevent chronic illness, manage high blood pressure and cholesterol, and improve bone density. The Mayo Clinic has splashed doubt on these claims, reporting that “research suggests that alkaline water is unlikely to significantly change blood pH” and that there’s “little credible evidence” for health benefits. An article breaking out these claims further in Medical News Today concluded “there is no evidence to support the health benefits of alkaline water, there is no recommended amount that improves health”.

‘A whole food diet is the best thing you can do for your internal flora’

A little closer to earth are probiotic waters. Unlike alkaline promises, the health science community are generally pro-probiotics. Gut-friendly foods like yoghurt, kimchi, miso and sauerkraut have been replenishing our microbiomes for much of human history, but have been increasingly spotlighted as gut health takes its place among top health and wellness trends. Now, there are several probiotic-enriched drinks around that are waterier than classic ferments, like kombucha and kefir.

“There is so much exciting research going on in the world of probiotics,” says Dr Johanna Simkin, senior curator of human biology and medicine at Museums Victoria, but, “the product/marketing side seems to have jumped enthusiastically on board, perhaps beyond where the genuine research is at!”

While she was quick to point out the research around probiotics is evolving, much of the industry focus has been on ingesting new microbes. Simkin says “the truth is you are set up with your own supply of microbes very early in life”. Rather than trying to introduce more, she suggests taking care of the trillions already in your gut. Luckily, like “detoxing”, this doesn’t require any expensive or specialty products.

“Simply put, a wholefood diet (non-processed food) is the best thing you can do for your internal flora,” Simkin recommends. “You can improve your microbiome within 24 hours simply by eating well … Beans, rice, sweet potato and other fresh fruit and veg are a great place to start.”

How water can work harder

Before you pitch your glass across the room, there are some situations where tap water can be helped along. VicHealth chief executive Dr Sandro Demaio stresses that “plain water from the tap is all most of us need to stay hydrated and healthy”. But it may not be enough when “when your body is losing fluids due to fever, diarrhoea or vomiting”. In these situations products with electrolytes (such as Hydralyte or sports drinks) can fulfil what at first seems like the kookiest claim, to help water be more hydrating.

“In your gut there is this sugar transporter that actively uptakes one sugar molecule and one water molecule,” Wilcox says. “So [water with electrolytes is] taken up from the gut faster than just drinking water alone ... it gets water across the gut membrane faster.”

But you only need that kind of speedy hydration if you’ve been exercising, sweating a lot, or are unwell (in which case you should also consult a doctor). There’s no need to turbocharge hydration for sitting on the couch.

It’s easy to say anything that gets you drinking water is good for you. But as Demaio cautions, “there is no evidence that any additives can make water healthier”. Other than being more costly than tap water, “many of these products can contain added sugar. Too much added sugar can lead to tooth decay and weight gain, increasing your risk of chronic health conditions like type 2 diabetes and heart disease.”

Perhaps most surprisingly, even our central fixation on optimal hydration may be misplaced. “You don’t actually need heaps of water … You get a lot of fluid through food,” Wilcox says.

Demaio puts it even more directly: “Hydration is a simple thing. You get thirsty, you drink water, repeat.”