Insulin 70/30 stock-out in Trinidad and Tobago: the peptide supply gap

What ran out, and for how long

In a release dated 15 July 2025, the Ministry of Health of Trinidad and Tobago said that "the temporary shortage of insulin 70/30, which began in early June, has now been resolved"¹. A shipment of 90,000 vials had arrived that Tuesday, distribution to public health facilities was to begin immediately, and a further supply was expected in August¹. The Trinidad and Tobago Guardian reported that the shortage "became a full stockout late last month", that it had intensified in the final week because the supplier underestimated regional demand, and that the Ministry asked for accelerated customs clearance and quality assurance to speed the stock to patients².

The Ministry put the cause abroad: "this shortage was caused by an international production and quality control delay"¹. It also stressed that "other types of insulin, including N and R insulin, remain available"¹.

Why insulin 70/30 matters in the public system

Insulin 70/30 is a premixed human insulin: 70 % isophane (NPH) and 30 % soluble (regular) insulin in one suspension, the product sold in the United Kingdom as Humulin M3, "insulin isophane biphasic human 30/70"⁶. Patients in Trinidad and Tobago get insulin and other diabetes drugs free through the Chronic Disease Assistance Programme (CDAP), which covers diabetes among 12 conditions for any citizen, through more than 250 pharmacies³. The need is large. In July 2025 the Health Minister, Dr Lackram Bodoe, cited the 2024 STEPS survey: "15.8% of the adult population in Trinidad and Tobago" aged 18 to 69 had raised fasting blood glucose, and the International Diabetes Federation put diabetes at 12.4 % of adults⁴. The same STEPS survey found 61.2 % of adults overweight or obese¹².

The insulin gap was not the last. In July 2026 pharmacy associations said metformin, losartan, amlodipine and rosuvastatin had been hard to get through CDAP, and the minister acknowledged "a supply chain issue as well, which we are addressing"¹³.

A regional and global pattern

Trinidad and Tobago was not alone. In April 2024 Barbados' Ministry of Health and Wellness said there was no shortage of any insulin class but "there is currently a scarce supply of Humulin 70/30", and limited pens per client per month to protect continuity of care⁵. In July 2025, one week after the Trinidad shipment, England's community pharmacy body relayed a supply notice that 10 mL vials of Humulin I, Humulin S, Humulin M3 and Humalog Mix25 "are being discontinued", with stocks expected to run out by April and May 2026⁶.

The structure of the market explains why a single production delay travels so far. When the World Health Organization launched its first insulin prequalification programme in November 2019, it said three manufacturers control most of the global market, that about 65 million people with type 2 diabetes need insulin but only half can access it, and that a survey had found "human insulin was available only in 61% of health facilities"⁷. A 2021 review in Diabetologia counted three multinational companies controlling "over 95% of global insulin supply" and noted that many governments lack policies on selection, procurement, supply, pricing and reimbursement of insulin⁸.

Insulin is a peptide: the first one

The discussion around peptides in Trinidad and Tobago is dominated by the GLP-1 drugs, and in January 2025 the Ministry said Novo Nordisk's local distributor had not filed an application to register Ozempic, although an application for a generic version had been received¹⁴. It is worth remembering where the class began. "Since the introduction of insulin almost a century ago, more than 80 peptide drugs have reached the market", according to a 2021 review in Nature Reviews Drug Discovery⁹. A century on, supply is concentrated in very few hands; when one producer's line slips, a small importing country feels it¹⁸.

Switching insulins: what the evidence says

During a stock-out, patients are moved to whatever is on the shelf, usually the separate N and R insulins the Ministry said were still available¹. Two Cochrane reviews help frame that switch. In type 2 diabetes, a 2018 review of 10 trials with 2,751 participants found "no clear benefits of short-acting insulin analogues over regular human insulin", with poor certainty of evidence¹¹. A 2020 review of 24 trials found that HbA1c effects were comparable between long-acting analogues (glargine, detemir) and NPH, but fewer participants had hypoglycaemia on the analogues¹⁰. On that evidence, human insulins remain a reasonable backbone for a public programme; the practical risk in a shortage is the unplanned change itself¹⁰¹¹.

What it means for practice

For prescribers, the 2025 episode is a reminder that a premix prescription depends on what CDAP pharmacies actually have in stock, and that the separate N and R insulins were the fallback the Ministry pointed to¹³. For policymakers, the WHO's answer was prequalification of more manufacturers, so that countries have "greater choice" of quality-assured insulin⁷⁸.