A new wave of “functional beverages” promising calm in a can is sweeping across UK supermarkets and online stores, marketed as natural stress relievers. Yet mounting evidence suggests these trendy “chill-out drinks” may pose unexpected health risks, particularly for vulnerable populations and those taking prescription medications.

These beverages typically combine herbal extracts, amino acids and adaptogens—compounds believed to help the body cope with stress. Popular ingredients include L-theanine from green tea, ashwagandha, lion’s mane mushroom and CBD (cannabidiol). Whilst functional beverages in UK appeal lies in their promise of natural relaxation without alcohol or caffeine, health experts are urging consumers to exercise caution.

The Science Behind the Claims

L-theanine has demonstrated ability to promote relaxation and reduce stress without causing drowsiness. Research indicates it influences brain chemicals such as serotonin and dopamine whilst lowering cortisol, the body’s primary stress hormone, creating a sense of calm without dulling alertness.

Magnesium, essential for healthy heart and brain function, has been linked to improved sleep and reduced insomnia. Studies suggest it supports melatonin production and binds to GABA receptors, helping quiet nerve activity and promote relaxation. Low magnesium levels have been associated with heightened depression risk, though more research is needed on supplementation benefits.

Ashwagandha, a traditional ayurvedic herb, has shown promise in clinical trials for lowering cortisol and reducing anxiety. However, long-term safety data remain limited, and the amounts used in studies typically exceed doses found in ready-to-drink functional beverages products.

Lion’s mane mushroom has demonstrated stress-reducing effects in small clinical studies, but the evidence base remains relatively slim. CBD, the non-psychoactive compound derived from cannabis, has shown early promise in reducing anxiety compared with placebo, although large, high-quality trials are still lacking.

Serious Drug Interactions: A Growing Concern

Despite their wholesome branding, these functional beverages in UK are not risk-free. CBD in particular has emerged as a significant concern for those taking prescription medications.

CBD alters liver enzyme activity through the CYP450 system, which is responsible for metabolising many prescription drugs. This can lead to dangerous drug interactions, particularly with antidepressants. When CBD inhibits these enzymes, it can cause altered drug concentrations in the bloodstream—either too little, rendering medications ineffective, or too much, increasing the risk of side effects.

Research has identified potentially serious interactions between CBD and commonly prescribed selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, antipsychotics, beta-blockers and opioids. Studies examining citalopram, fluoxetine and sertraline found that CBD can significantly affect their metabolism, warranting clinical vigilance for treatment-emergent adverse effects.

Taking CBD alongside substances that cause sleepiness—including benzodiazepines, antidepressants or alcohol—may lead to increased fatigue and potentially dangerous accidents when driving. The combined sedative effects can be substantially greater than either substance alone.

Regulatory Shake-Up: CBD Dose Slashed

In a significant development highlighting safety concerns, the UK Food Standards Agency (FSA) dramatically reduced its recommended daily CBD limit from 70mg to 10mg in October 2023. This represents an 85% reduction based on new evidence about long-term health risks.

The FSA and Food Standards Scotland made this change following reviews by independent scientific committees, which identified risks of liver damage and thyroid problems with higher lifetime CBD consumption. Professor Robin May, FSA chief scientific adviser, explained: “The more CBD you consume over your lifetime, the more likely you are to develop long-term adverse effects, like liver damage or thyroid issues.”

Critically, the new 10mg limit has nothing to do with effectiveness at this dose—because there is no proven effect at such low levels. When benefits have been evident in studies, they typically occur at much higher doses, approximately five times the previous maximum recommended intake.

Many functional beverages in UK currently available contain CBD levels exceeding the new 10mg daily limit in a single serving. Some canned CBD beverages contain 15-30mg per can, whilst CBD oils can contain 1,000-3,000mg per bottle.

Quality Control: A Significant Gap

The functional beverage market remains only lightly regulated, meaning potency and purity of ingredients can vary considerably between brands. This represents a particular worry for people who are pregnant, breastfeeding or managing chronic health conditions.

Laboratory testing has revealed that CBD products often fail to contain the advertised CBD content due to inaccurate labelling. The lack of regulatory oversight means consumers cannot reliably verify what they’re actually consuming.

Beyond CBD, other popular ingredients present concerns. Ashwagandha can interfere with thyroid medications and immunosuppressants. High magnesium intakes can cause diarrhoea and may clash with certain antibiotics or osteoporosis medicines. Lion’s mane appears well tolerated in limited studies, but researchers know little about its long-term effects.

Who Should Avoid Functional Beverages in UK?

Certain populations face heightened risks from these drinks and should exercise particular caution or avoid them entirely.

Pregnant and breastfeeding women lack sufficient safety evidence for adaptogen use during pregnancy or nursing. Some functional beverages in UK may contain ingredients known to be risky, such as THC, which can harm a developing foetus or pass into breast milk.

Children should avoid these products as little research has examined adaptogen use in young people. Most adaptogen drinks are formulated with adult doses in mind, making them potentially inappropriate for younger users. Additionally, CBD beverage packaging often lacks childproof features, creating accidental consumption risks.

People taking prescription medications must be especially vigilant. The FSA continues to advise that CBD should not be taken by people taking medication unless under medical supervision. Drug interactions can render medications ineffective or cause dangerous side effects.

Those with chronic health conditions face specific risks. Reishi mushroom can lower blood sugar and blood pressure or slow blood clotting. Chaga should be avoided by those with kidney problems due to high oxalate levels. Cordyceps may exacerbate multiple sclerosis, lupus or other autoimmune conditions. Lion’s mane can affect blood sugar levels and increase organ rejection risk in transplant patients.

The Marketing Myth Versus Medical Reality

Part of the appeal of functional beverages in UK lies in their branding as natural, non-intoxicating ways to unwind. For young professionals seeking midday mental resets, cracking open a can of calm seems tempting. Sometimes the ritual matters as much as the recipe—the act of slowing down can create its own sense of pause.

However, medical professionals emphasise that “natural” does not automatically mean safe. Seemingly harmless foods like grapefruit, broccoli and well-done steak can all interfere with drug metabolism. The concentrated herbal compounds in functional beverages in UK can pose similar or greater risks.

In herbal medicine, substances like ashwagandha or ginseng are not meant for perpetual use. These potent herbals are traditionally given for short courses whilst patients work on lifestyle factors with practitioners. The daily consumption model promoted by functional beverage marketing contradicts traditional herbal medicine principles.

No Substitute for Professional Care

A can of calm may offer brief relief, but these functional beverages in UK are no substitute for professional mental health care. Chronic anxiety, depression or ongoing sleep problems require proper diagnosis and treatment. Whilst chill-out drinks might help take the edge off a hectic day, they cannot address underlying causes of stress.

The bioavailability of active ingredients in beverage form raises additional questions. Medical experts note there’s no particular advantage to CBD or adaptogens being in liquid or infused form—the delivery method doesn’t significantly impact efficacy.

What Consumers Must Know

Before incorporating functional beverages in UK into daily routines, consumers should take several precautions:

Consult healthcare providers before using these products, especially when taking any prescription medications. Drug interactions can be serious and are not always immediately apparent.

Check labels carefully for CBD content and total daily intake across all products. With the FSA’s new 10mg daily limit, many single servings now exceed recommended safe levels.

Choose reputable brands that provide third-party testing certificates. Quality and purity vary considerably across the market.

Be sceptical of health claims. Marketing often exaggerates benefits beyond what scientific evidence supports. The lack of familiarity with ingredients like adaptogens and nootropics can create confusion exploited by misleading advertising.

Monitor your consumption. If using multiple CBD or adaptogen products, total daily intake can quickly exceed safe levels.

Avoid during pregnancy and breastfeeding. Insufficient safety data means potential risks to developing foetuses and infants.

The Path Forward

These functional beverages in UK tap into a broader wellness trend reflecting our collective desire to slow down and feel better. Their ingredients show some promise in scientific studies, and when used mindfully and in moderation, they may play a small part in managing everyday stress.

However, the wellness industry’s rapid expansion has outpaced regulatory oversight. The dramatic reduction in recommended CBD intake highlights how initial safety assumptions can change as more evidence emerges. What seemed safe at 70mg daily just two years ago is now considered potentially harmful for long-term consumption.

Consumers must approach functional beverages in UK with informed caution rather than uncritical enthusiasm. Just don’t mistake them for cure-alls: a chilled drink can provide a pleasant pause, but lasting calm still depends on the habits and support systems that lie beyond the can.

The quality control issues, drug interaction risks, and regulatory gaps mean these products require the same careful consideration as any other substance that affects brain chemistry and bodily functions. “Natural” wellness drinks deserve the same scrutiny we’d apply to pharmaceutical products—perhaps more so, given the lighter regulatory framework governing their sale.

Source: dbrecoveryresources