Walk into any pharmacy and the prenatal supplement shelf tells a familiar story: large capsules/tablets and serving sizes that require patients to swallow two or more daily, often on an already-nauseated stomach. For a population experiencing nausea rates as high as 70% during the first trimester, this approach borders on counterintuitive (1).

The assumption embedded in standard prenatal formulations is that compliance and tolerability are the patient's problem to solve. The clinical reality is different. Poor tolerance leads to inconsistent intake (2), and inconsistent intake may lead to nutrient shortfalls during the most developmentally sensitive window of human life. Format is not merely a consumer preference; it is a clinical concern.

Iron deficiency (ID) has shown to affect up to 70% of pregnant women, and the global prevalence of iron deficiency anaemia (IDA) ranges between 2.4% to 66% across both developed and developing countries (3, 4). IDA has been linked to several maternal and foetal health risks, even before ID progresses to IDA (5). As a preventative measure, the World Health Organisation (WHO) and other international guidelines, recommend that all pregnant women, regardless of iron status, receive daily iron supplementation alongside folic acid (5).

Conventional iron forms, such as ferrous sulphate, carry a well-documented tolerability burden, including constipation, nausea, and gastrointestinal tract (GIT) discomfort, that frequently leads patients to discontinue supplementation altogether (6). A nutrient that is not taken does not provide clinical value, regardless of the dose on the label.

To address this concern, there has been a growing trend among newer pregnancy supplement brands to remove iron altogether; positioned as a tolerance-driven decision, with the rationale that gastrointestinal burden is reduced and that practitioners can prescribe therapeutic iron separately at higher doses when clinically indicated. On the surface, this appears considered. In practice, it represents a significant gap in preventive nutritional care.

Given IDA affects an estimated 36.5% of pregnant women globally (5), designing a prenatal supplement that omits iron on the basis that its delivery is challenging, is solving a formulation problem by creating a clinical one.

The scientific literature increasingly supports this position. Recent evidence shows that doses of elemental iron as low as 20mg, can achieve equivalent efficacy to doses as high as 80mg in the prevention and management of IDA, with a substantially reduced incidence of adverse effects (7).

Furthermore, a 2023 systematic review and meta-analysis of randomised controlled trials in non-anaemic, iron-replete pregnant women found that iron supplementation reduced the risk of iron deficiency anaemia at term by approximately 49% (RR 0.51; 95% CI 0.38–0.70) and reduced the incidence of low birth weight (RR 0.30; 95% CI 0.13–0.68), with no clear evidence of clinically significant harm reported (8). This highlights an opportunity for well-formulated prenatal supplements to deliver meaningful, preventive iron support without the tolerance burden that has historically driven both patient discontinuation and practitioner hesitation.

Next-generation iron forms represent a meaningful clinical advance. Emulsified microsomal ferric pyrophosphate (EMFP) is one such technology that has demonstrated an improvement in tolerance over conventional iron salts while maintaining equal efficacy (9). EMFP bypasses the conventional absorption route, preventing free iron from interacting with the gut lining, the mechanism responsible for most gastrointestinal adverse effects associated with standard oral iron. Results showed no statistical difference in bioavailability and efficacy to higher doses of ferrous ascorbate, with a significant reduction in incidence of adverse events (9).

Critically, this format also addresses taste aversion, a barrier to adherence that is rarely discussed in clinical literature but is highly relevant to pregnant patients who frequently report heightened sensory sensitivity (10). Efficacy at lower doses, combined with superior tolerability and taste masking, is where clinical evidence meets a patient-centred approach.

Beyond ingredient selection, the question of delivery format deserves equal clinical consideration. Standard prenatal supplements have long defaulted to compressed tablet or capsule formats. While they offer some conveniences (11), to meet the substantially increased micronutrient requirements of pregnancy, manufacturers must either increase tablet size, increase the number of tablets per serve, or compromise on nutrient scope. Some do a combination of all three. For a population in which up to 70% experience nausea and vomiting of pregnancy, and in which tablet size is frequently cited as a primary reason for reduced supplementation adherence (11), this represents a fundamental design shortfall.

Gummy and chewable formats have emerged as a popular response to this problem, and their palatability can be advantageous. However, the physical constraints of gummy technology impose a hard ceiling on clinical utility. The dose and volume required to meaningfully deliver nutrients such as iron, calcium and magnesium, alongside a comprehensive micronutrient panel, are difficult to accommodate within a gummy matrix without compromising either nutrient integrity, texture, taste, cost or serving size. Many gummy prenatal supplements omit certain nutrients entirely or deliver them at levels that fall well short of pregnancy requirements.

Oral dissolving powder delivered in a single-serve sachet provides an innovative solution to address these shortfalls. The format accommodates the full nutrient scope required across the preconception, pregnancy, and postnatal continuum within a single daily serve, without the volume constraints of compressed formats or the dose limitations of gummy technology. Administration is flexible: dissolved in water or taken directly onto the tongue; a practical consideration for women managing nausea (Figure 1).

Figure 1. Powder supplement formats allow for improved nutrient scope and buccal absorption.

The clinical implications extend beyond convenience. The powder format creates meaningful capacity to address nutrients that are consistently under-delivered in standard prenatal supplements, calcium being the most clinically significant example. Despite calcium's well-established role in foetal and maternal health, most prenatal tablets fail to reach even 25% of the pregnancy recommended daily intake, constrained by the physical space. For certain countries where calcium intake is already below recommendations in a significant proportion of the population, including many APAC countries, this gap is of clinical relevance (12). A sachet format removes the dose ceiling, enabling formulators to make deliberate, evidence-informed decisions about calcium and similarly overlooked nutrients, rather than working around the limitations of the delivery vehicle.

Discussions of prenatal supplement formulation have historically centred on what is delivered; the nutrient, the dose and the ingredient form. Less attention has been given to how delivery itself shapes nutritional outcomes.

The oral mucosa represents a highly vascularised absorptive surface with direct access to systemic circulation, bypassing the hepatic first-pass metabolism that governs conventional oral tablet and capsule delivery (13). Where a compressed tablet must first disintegrate, dissolve, and survive the GIT environment before reaching absorptive surfaces, an oral dissolving formulation initiates contact with the mucosal epithelium immediately upon administration. For specific nutrients, this distinction in absorptive pathway can have meaningful clinical impact.

Vitamin B12 is one such example. Conventional oral B12 absorption is a complex, multistep process dependent on intrinsic factor secretion by gastric parietal cells, intact ileal receptor function, and adequate gastric acid production (14). Subclinical deficiency is estimated to affect up to 26% of the general population and is more common in older adults, those with underlying GIT disorders and/or consume predominantly plant food diets (14). A reliance on optimal intake and digestive function is particularly relevant in pregnancy, where GIT motility changes, nausea-driven dietary restriction, and altered gastric physiology (15) can collectively compromise B12 status at a time where daily requirements are increased (16). Buccal B12 administration has been investigated as an alternative due to its ability to bypass traditional absorption routes, enabling direct diffusion across the buccal epithelium into the submucosal capillary network. Studies have demonstrated that buccal B12 delivery can achieve equivalent results to traditional tablet forms in deficient individuals (14, 17); a finding that holds promise for women who struggle to take traditional tablet formats during pregnancy.

It bears acknowledging that the buccal absorption literature in the specific context of pregnancy supplementation remains an area where further dedicated research is needed.

Prenatal supplementation sits at the intersection of one of the most consequential areas of nutrition science. The standards applied to ingredient selection, formulation design, and evidence evaluation in this category should reflect that gravity.

Tolerability is not secondary to efficacy; in a population that struggles to comply with supplementation, they are inseparable.

What this approach demands, however, is precision. Combining the nutrient scope of a comprehensive prenatal formula, the dose integrity required for clinical relevance, and the palatability characteristics that sustain daily compliance over the course of a pregnancy is not a simple formulation exercise. Taste, solubility, ingredient interactions, and sensory profile must be considered alongside efficacy, remembering a formula that a patient does not consistently take has little clinical value, regardless of what is on the label. The convergence of dose, format, nutrient scope, tolerability and palatability is the central formulation challenge of prenatal nutrition, and the standard against which all pregnancy supplement formats should be measured.