Self-management is now part of everyday clinical practice. Patients routinely treat symptoms with OTC medicines, vitamins, minerals, and ‘wellness’ products before they see a doctor, and sometimes instead of seeing one. In many cases that is entirely appropriate.

Good self-care can improve access, support continuity, reduce unnecessary consultations, and give patients a sense of control over recurrent problems. But it also creates a recurring ethical tension for doctors and pharmacists: When does sensible symptom management become delayed diagnosis, inappropriate supplementation, or avoidable harm?

In South Africa, that tension sits within a regulatory framework in which the Medicines and Related Substances Act governs medicines and related products, while the South African Health Products Regulatory Authority (SAHPRA) makes clear that health supplements are intended for low-risk indications and not for broad, weakly substantiated disease-treatment claims.

For clinicians, the practical ethical question is rarely whether a product is categorically ‘good’ or ‘bad’. The real question is whether the product is being used in the right patient, for the right reason, for the right duration, with the right information. That is where the familiar principles of beneficence, non-maleficence, respect for autonomy, and honest communication become concrete.

Patients are entitled to make choices about self-care, but autonomy is only meaningful if it is supported by accurate counselling, realistic expectations, and clear warning signs for referral. SAHPRA’s guideline on health supplements safety and efficacy and its guideline on risk levels of claims for complementary medicines are useful reminders that product claims should remain proportionate to the evidence.

Three common scenarios illustrate the problem especially well:

1. Diabetic peripheral neuropathy (DPN) and vitamin B supplementation
2. Nasal congestion and rebound congestion
3. Magnesium supplementation in patients who may or may not actually need it.

They seem unrelated, but they all involve the same risk, namely, a symptom that is transformed into a purchasing decision before it is properly interpreted.

Diabetic neuropathy, metformin, and the temptation of a simple vitamin answer

DPN symptoms in diabetes are common, distressing, and often chronic. Tingling, numbness, burning pain, altered sensation, and nocturnal discomfort drive many patients to seek help beyond glycaemic control alone.

In practice, one of the first self-management strategies patients encounter is vitamin B supplementation, often in the form of a ‘nerve support’ preparation or a general B-complex. The attraction is obvious, the product sounds low risk, relatively inexpensive, and biologically plausible. But that apparent simplicity is exactly what makes the issue ethically interesting.

The most relevant starting point is the local diabetes treatment context. In South Africa’s Primary Healthcare Standard Treatment Guidelines and Essential Medicines List (2024), metformin remains a cornerstone of first-line therapy for type 2 diabetes.

That matters because the most clinically plausible reason to think carefully about vitamin B12 in a patient with DPN symptoms is not simply that ‘vitamins help nerves’, but that long-term metformin use may contribute to vitamin B12 depletion, which can complicate the assessment of neuropathy.

South African evidence supports that concern. A recent South African cohort analysis published in the Journal of Endocrinology, Metabolism and Diabetes of South Africa found that metformin users had lower median vitamin B12 levels than non-users, with an association between metformin exposure and borderline-low vitamin B12 levels and noted that a prior South African study found vitamin B12 deficiency in ~28% of patients on metformin therapy.

In practical terms, that means vitamin B12 status should be considered when a patient on chronic metformin presents with new, worsening, or atypical neuropathic symptoms, especially where there are anaemia, dietary risk, or other possible contributors.

That evidence does not mean every patient with DPN should automatically receive a vitamin B supplement. Ethically, that is the point. It is one thing to correct a plausible or demonstrated deficiency, it is another to imply that a supplement is a general treatment for diabetic neuropathy without distinguishing between diabetic nerve injury, metformin-associated B12 depletion, alcohol-related neuropathy, renal disease, thyroid disease, or other neurological causes.

Once a vitamin product is framed as the answer, the risk is that proper assessment is quietly displaced. The patient may feel they are being treated, while the actual diagnostic question remains unresolved.

For doctors, this means resisting the slide from symptom to supplement without first asking whether the neuropathy is typical, whether it is new or worsening, whether the patient is on long-term metformin, and whether B12 status has been checked or should reasonably be checked.

For pharmacists, it means that ‘something for neuropathy’ should not always trigger a supply response, sometimes it should trigger a referral response. A short counselling exchange about symptom duration, metformin use, diet, alcohol intake, and whether there has already been medical assessment may prevent false reassurance and delay. The ethical issue is not that vitamin B products are illegitimate. It is that the most defensible use of them is targeted, transparent, and tied to a credible mechanism.

There is also a communication issue here. Patients often hear language such as ‘this helps nerves’ or ‘this is good for neuropathy’, which sounds precise but is often not. In a supplement market, that kind of phrasing can blur the distinction between nutritional support and disease treatment.

SAHPRA’s framework matters precisely because it requires a more disciplined approach to claims. Under SAHPRA’s Complementary Medicines framework and Health Supplements Safety and Efficacy guideline, health supplements are intended for low-risk indications and support claims, while higher-risk disease-related claims require stronger substantiation and may move into the regulatory space of medicines rather than supplements. In other words, the regulatory line reinforces the ethical one, support may be appropriate, but overclaiming is not.

Nasal congestion and the ethics of foreseeable overuse

If DPN illustrates the ethical risk of under-investigation, nasal congestion illustrates the ethical risk of foreseeable misuse. Topical nasal decongestants can provide rapid and often dramatic relief. For patients with a cold, allergic rhinitis, or acute nasal obstruction, that immediate improvement is precisely what makes these products attractive. Yet it is also what makes them potentially problematic when the limits of use are not clearly understood.

The most relevant evidence comes from SAHPRA-approved product information. Current South African patient information leaflets and professional information for oxymetazoline-containing products consistently warn against prolonged use because of the risk of rebound congestion, drug-induced rhinitis, and in some cases rhinitis medicamentosa (RM).

These warnings matter because the harm is highly predictable. Patients are not usually overusing these sprays because they are reckless, they are overusing them because the product works, the relief wears off, and the spray appears to solve the problem again. A cycle can follow in which the medicine used to relieve nasal obstruction becomes part of the cause of persistent obstruction. Ethically, this is not simply a matter of patient compliance. It is a matter of whether clinicians and pharmacists take predictable patterns of misuse seriously enough.

This is where pharmacists have an especially important gatekeeping role. A patient asking for another bottle may not need a second sale, they may need recognition of rebound congestion, advice on stopping the spray, and guidance toward safer longer-term management of the underlying cause, such as allergic rhinitis. In practice, one simple question can change the encounter: How many days have you already been using this spray? That shifts the focus from product supply to symptom interpretation.

Doctors, too, should be cautious about simply endorsing ongoing decongestant use without revisiting the diagnosis. Persistent congestion should prompt consideration of allergic rhinitis, chronic rhinosinusitis, irritant exposure, structural obstruction, or medication-induced rhinitis rather than reflex continuation of topical vasoconstrictors. Oral decongestants are not necessarily a benign alternative either, especially in patients with hypertension or cardiovascular disease.

South African regulatory and professional guidance supports this counselling role. SAHPRA’s Guideline for Patient Information Leaflet for Human Medicines (Categories A–D) requires clear, patient-readable instructions for safe use and advice on what to do if symptoms persist. The South African Pharmacy Council Code of Conduct reinforces the broader ethical principle that patients should not be left with only the attractive side of a product’s story and none of its foreseeable risks.

In this context, good care is not about withholding short-term relief. It is about ensuring that a medicine designed for brief symptom control does not quietly become a cause of chronic symptoms through insufficient counselling.

Magnesium supplementation and the problem of the ‘universal fix’

Magnesium occupies a different space in self-care. It is not usually marketed as a rapid symptomatic rescue in the way a nasal spray is, and it is not tied to a single chronic disease pathway in the way vitamin B12 may be with metformin.

Instead, it is often presented as a broad solution for cramps, poor sleep, fatigue, stress, constipation, migraine, or general ‘low energy’. That broad appeal is precisely why careful patient selection matters.

The most useful starting point is not a foreign supplement fact sheet, but the distinction between clinical correction of deficiency and low-risk health supplement use under South African regulation. SAHPRA’s framework for Complementary Medicines and its Health Supplements Safety and Efficacy guideline make it clear that health supplements are intended for low-risk indications, such as maintenance of health, support of normal physiological function, and relief of minor symptoms. This is highly relevant to magnesium, because it is often promoted in ways that blur the line between nutritional support and treatment of complex or poorly defined clinical complaints.

From a clinical perspective, a more disciplined, profile-based approach is preferable. In practice, magnesium assessment and supplementation may be entirely justified in patients with chronic diarrhoea, gastrointestinal (GI) disease or malabsorption, poor dietary intake, alcohol dependence, suspected biochemical depletion, or certain medication exposures (for example, diuretics or long-term proton pump inhibitors).

That approach is consistent with routine laboratory-based and general practice management of hypomagnesaemia in South Africa, where the focus is typically on identifying who is actually at risk, rather than assuming that non-specific symptoms automatically reflect magnesium deficiency.

In contrast, indiscriminate supplementation in patients with vague complaints can become a form of pseudo-precision, it sounds tailored, but it is not. Fatigue, cramps, poor sleep, and low mood are real symptoms, but they are not magnesium-specific symptoms.

There is also a safety boundary that is often neglected because magnesium is perceived as ‘natural’ and therefore harmless. In reality, the main clinical issue is not that magnesium is dangerous in ordinary use, but that patient context matters.

Good clinical practice in suspected hypomagnesaemia involves looking for underlying causes, considering associated electrolyte abnormalities, reviewing concurrent medicines, and using greater caution in patients with significantly reduced renal function, where impaired renal excretion increases the risk of hypermagnesaemia. This is why casual recommendation of magnesium in patients with kidney disease is much harder to justify than it may initially appear.

For pharmacists, magnesium is a classic example of where counselling should move beyond ‘this may help’ to ‘tell me a bit about why you want it, what else you take, and whether you have kidney problems or ongoing GI issues’.

For doctors, it is a reminder not to endorse a supplement simply because it appears low risk or familiar. The question is not whether magnesium has a place. It clearly does. The question is whether the recommendation is patient-specific, honest about limits, and alert to the possibility that a supplement may be standing in for diagnostic uncertainty.

Again, SAHPRA’s framework is central. Health supplements may occupy a legitimate low-risk space, but that space is not limitless. Once magnesium products are framed as universal solutions for complex, non-specific, or disease-related complaints, the ethical and regulatory concerns begin to converge.

The issue is not that magnesium products exist, but that the rhetoric around them can outrun both the evidence and the patient’s actual clinical profile. In this setting, the most defensible approach is not blanket endorsement, but careful selection, proportionate counselling, and restraint in claims.

What doctors and pharmacists should take from these cases

These three scenarios point to the same core lesson. Self-care is not the problem. Unsupported self-care is. In DPN, the risk is that supplementation substitutes for assessment of vitamin B12 deficiency or other causes.

In nasal congestion, the risk is that effective short-term relief turns into treatment-induced chronic congestion because duration limits were not stressed. In magnesium use, the risk is that a real nutrient becomes a default answer to symptoms that may have many causes and may need investigation.

The professional task is therefore interpretive rather than simply transactional. It means asking what the symptom likely represents, what the patient has already tried, how long the problem has been present, what comorbidities and medicines matter, and whether this is still a low-risk self-management scenario or has crossed into something that warrants clinician-guided care.

That approach is consistent with the broader ethical emphasis on informed choice and with South African professional standards. Even where a product is appropriate, the counselling should include what benefit is realistically expected, what risks or limits matter, and when reassessment is necessary.

In the end, the most ethical approach to self-managed conditions is not paternalistic restriction and not laissez-faire ‘retailism’. It is disciplined support. Doctors and pharmacists should help patients use self-care tools well, not merely use them often. That means better questions, clearer warnings, more careful claims, and timely referral when a product starts to replace clinical judgement rather than serve it.

Dr Marietjie Botes is a lawyer and academic researcher specialising in biotechnology law, neuroethics, data governance, and intellectual property law. Currently an exchange scholar at the University of Texas (United States), she transitioned from a 20-year career as a practising attorney in health law and biotechnology to academia, where she focuses on interdisciplinary research at the intersection of science, technology, law, and ethics. She holds BProc, LLB, LLM (Intellectual Property Law), and a PhD in Biotechnology Law. Her research explores the regulation and ethics of gene therapies, gene and stem cell research, the use of big geospatial data during pandemics, and digital health technologies such as brain-computer interfaces. She has published widely, co-edits a Springer Nature digital ethics special edition, is an elected  Academy of Science of South Africa member, and contributed legal expertise to South Africa’s Covid-19 country reports.

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