You’ve raised concerns that many iron supplements sold in Australia contain very little actual iron. What did you find?

I have found that consumers are generally unaware of the appropriate dose of iron to take to treat iron deficiency. As a result, many people take low-dose products often called 'iron supplements' without realising they contain no more iron than a slice of bread or a bowl of cereal.

There are many iron supplements on the market that do provide an appropriate iron dose (100–200 mg elemental iron per day), but this big dose of oral iron often causes unpleasant gastrointestinal side effects such as constipation, bloating and cramps.

As a result, a range of iron products have emerged on the market that claim to be 'gentle on the stomach' and 'easy to digest' but only contain a teeny-tiny amount of iron, usually 5-10mg per dose. This is a reasonable maintenance iron dose, as it is about the same amount of iron gained from the average Western diet (10–15 mg per day, or 7 mg per 1000 kcal) but you would have to take 10–20 doses of these low strength products per day to be an effective treatment dose of iron deficiency.

Is the issue here misleading marketing, regulatory loopholes, consumer misunderstanding – or a mix of all 3?

Misleading marketing and labelling are the main problems here, so stricter regulation by the Therapeutic Goods Administration (TGA) would help. Much could be addressed by simply limiting use of the term ‘iron supplement’ to products containing say 25-50 mg per dose or more and products with 10 mg or less only allowed to claim benefit for 'maintenance of iron levels' and banned from claiming use for iron deficiency.

Products with minuscule iron doses simply should not be allowed to call themselves an iron supplement and there should be tighter controls on the therapeutic and tolerability claims such as 'improves energy levels', 'gentle on the stomach' or 'to prevent nutritional iron deficiency' as these claims are misleading with negligible iron in the product.

Even health professionals can be unaware that low dose iron products exist, as they are more familiar with the higher dose iron supplements used in medical settings. So, if health professionals don’t ask their patients exactly what product they’ve been taking and how much iron it contains, they can mistakenly believe the patient’s iron deficiency is not responding to treatment so may pursue more intensive interventions such as iron infusions.

How strict is supplement regulation in Australia compared to prescription medicines?

While registered medicines must submit safety and efficacy data to the TGA before they gain marketing approval, products like supplements are not required to submit any data to prove they are safe or effective. All they have to do is list their ingredients, comply with permitted therapeutic claims and allow their manufacturing facilities to be inspected.

Unfortunately, this system only considers potential toxicity of the ingredients and pays little attention to things like false advertising, new adverse reactions, drug interactions, dosage issues and product adulteration.

The TGA is underfunded for all the amazing work they do, so I appreciate they can’t regulate everything. We can help them, however, by reporting problems when they arise, so they can become more aware and do something about it.

Beyond iron, are there other supplements where the active ingredient is often much lower or less effective than people assume?

Of course! Consumers must face the fact that natural health products and supplements are not lollies, and they don’t work by magic. If consumers want them to be effective, then they should accept that they are pharmacologically active substances, i.e. drugs. Like all drugs, they have the potential for under-dosing, over-dosing, adverse reactions and drug interactions. There’s an old saying that goes, 'the only difference between a drug and a poison is the dose'.

If in doubt, talk to your pharmacist or GP for advice.

Do you think the public overestimates what supplements can do for health?

Most consumers overestimate what supplements can do, but this is largely due to the vague and non-specific claims they make such as 'supports eye health', 'balances hormone levels' or 'maintains immune function'. These claims sound good, but they are so broad they could be interpreted however you like.

Instead, I encourage consumers to have functional goals for their supplements – indeed, for all their medicines. Don’t use a supplement without having a precise therapeutic goal in mind, and make that goal SMART: specific, measurable, achievable, reasonable and time restricted.

What questions should people ask a pharmacist or health professional before buying a supplement?

Make an appointment to ask your pharmacist for advice on a functional and SMART goal for the supplement you wish to take.

But don’t stop there: ask the pharmacist to also advise you on the potential risks of the supplement. They are only safe if the potential benefits outweigh the risks.

The 6 potential risks to consider when taking a new supplement are:

• Adverse effects: what are the potential short- and long-term side effects of this supplement?
• Burden: to what extent will this supplement add to my current medication burden, which puts me at risk of medication errors and non-compliance?
• Cost: what is the cost of this supplement, especially over time? Is the benefit worth this cost? Is there a more cost-effective intervention?
• Delay of more effective therapy: is there a chance I’m wasting valuable time if I try this supplement rather than something more effective – thereby delaying treatment?
• Interactions: what are the potential interactions between the ingredients in this product and my other medicines and supplements? How significant are the outcomes of those interactions for my health?
• Failure of therapy, fraud and false hope: is there any chance that this supplement is making false or fraudulent claims? How important is that to me?