Insulin Aspart (NovoRapid, Fiasp, Trurapi)

Insulin aspart is a rapid-acting insulin analogue used to treat diabetes. It is usually taken around mealtimes to control blood sugar spikes, alongside a longer-acting "basal" insulin. In the UK it is available under the brand names NovoRapid, Fiasp and the biosimilar Trurapi.

This article is for information only. It is not medical advice. If you need help with your insulin, speak to your pharmacist, GP or diabetes team. In an emergency, call 999.

Current UK Insulin Aspart Supply Status

CPE notes that Fiasp products are not interchangeable with Trurapi because of differences in bioavailability.

What to do if your usual insulin is unavailable

• Do not stop taking insulin. Stopping insulin can cause diabetic ketoacidosis (DKA), which can be life-threatening.
• Do not share pens or needles, and do not change your insulin type, brand or device except under medical supervision. Speak to your pharmacist, prescriber or diabetes team.
• Contact your pharmacist, GP or diabetes specialist as soon as possible if your usual pen or cartridge is out of stock.
• If you are running low and cannot get insulin, or you have signs of high blood sugar or ketones, seek medical advice immediately. In an emergency, call 999.
• Pump users: talk to your diabetes team about any pump supply problem or device change.

What Is Insulin Aspart Used For?

Insulin aspart is used to treat diabetes mellitus in adults, adolescents and children aged 1 year and above. It is a rapid-acting "bolus" or "mealtime" insulin, meaning it is taken to control the rise in blood glucose that happens after eating.

It is normally used together with an intermediate-acting or long-acting insulin that provides background coverage through the day and night. Some people also use it in an insulin pump for continuous subcutaneous insulin infusion.

Source: NovoRapid SmPC section 4.1

How It Works

Insulin aspart is a man-made insulin that is very similar to the insulin your body makes, but it is absorbed faster after an injection. This means it starts working more quickly than soluble human insulin.

• Onset of action: 10–20 minutes after injection
• Maximum effect: 1–3 hours after injection
• Duration of action: 3–5 hours

Because it acts quickly, it should generally be taken immediately before a meal. If necessary it can also be taken soon after a meal. It helps glucose move from the bloodstream into cells, where it is used for energy, thereby lowering blood sugar levels.

Sources: NovoRapid SmPC section 4.2, EMA EPAR for NovoRapid

Forms and Strengths Available in the UK

All rapid-acting insulin aspart products in the UK are 100 units/ml clear, colourless solutions for injection. They come in several device types:

Fiasp is a faster-acting formulation of insulin aspart that also contains nicotinamide (vitamin B3). According to its SmPC, it can be taken up to 2 minutes before a meal, or up to 20 minutes after starting a meal if needed.

NovoMix 30 is a separate pre-mixed biphasic insulin that contains 30% insulin aspart and 70% insulin aspart protamine. It is a suspension (not a clear solution) and is used differently from rapid-acting insulin aspart alone.

Sources: eMC search results, NovoRapid SmPC section 2, Fiasp SmPC section 4.2

Brand and Generic Names

• NovoRapid (Novo Nordisk) — the original brand
• Fiasp (Novo Nordisk) — faster-acting version
• Trurapi (Sanofi) — a biosimilar insulin aspart
• NovoMix 30 (Novo Nordisk) — a pre-mixed biphasic insulin containing insulin aspart and insulin aspart protamine

Source: eMC search results

Invention and Approval History

NovoRapid's marketing authorisation holder is Novo Nordisk A/S (Denmark). The European Medicines Agency records an opinion adopted on 20 May 1999, and the European Commission granted a marketing authorisation valid throughout the EU on 7 September 1999.

The biosimilar Trurapi was first authorised on 25 June 2020, according to its UK SmPC.

Source: EMA EPAR for NovoRapid

How Insulin Aspart Is Made

Insulin aspart is produced using recombinant DNA technology:

• NovoRapid and Fiasp are produced in Saccharomyces cerevisiae (baker's yeast).
• Trurapi is produced in Escherichia coli (E. coli) bacteria.

Insulin aspart differs from human insulin by one amino acid: proline at position B28 is replaced by aspartic acid.

Sources: NovoRapid SmPC section 2, Trurapi SmPC section 2

Common Side Effects

The most common side effect is hypoglycaemia (low blood sugar), which may affect more than 1 in 10 people. Signs include cold sweat, cool pale skin, headache, rapid heartbeat, feeling hungry, tremor, anxiety, confusion, drowsiness and vision changes.

Other side effects include:

• Injection site reactions — pain, redness, hives, itching, bruising or swelling (these usually go away within a few days to a few weeks)
• Lipodystrophy — fatty tissue may shrink (lipoatrophy) or thicken (lipohypertrophy) under the skin if you inject in the same place repeatedly
• Cutaneous amyloidosis — protein build-up causing lumps under the skin (frequency not known)
• Vision changes — usually temporary when starting insulin
• Swelling around joints (oedema) — usually temporary

Sources: NovoRapid SmPC section 4.8, NovoRapid PIL

Serious Side Effects and When to Get Urgent Help

Severe hypoglycaemia can lead to unconsciousness, convulsions, temporary or permanent brain damage, and even death if not treated. If someone with diabetes passes out from low blood sugar, turn them on their side and get medical help straight away (in an emergency, call 999). Do not give them food or drink, because of the risk of choking.

Diabetic ketoacidosis can occur if insulin doses are missed or stopped, especially in type 1 diabetes. Warning signs include thirst, frequent urination, nausea, vomiting, drowsiness, flushed dry skin, dry mouth, loss of appetite and a smell of acetone on the breath. This is a medical emergency — seek urgent help.

Serious allergic reactions (anaphylaxis) are very rare (less than 1 in 10,000 people) but potentially life-threatening. Seek medical advice immediately if signs of allergy spread to other parts of your body, or if you suddenly feel unwell and start sweating, start being sick, have difficulty breathing, have a rapid heartbeat or feel dizzy. In an emergency, call 999.

Sources: NovoRapid SmPC sections 4.4, 4.8, 4.9, NovoRapid PIL

Interactions and Cautions

Some medicines can raise or lower your blood sugar, meaning your insulin dose may need adjusting. Tell your doctor, nurse or pharmacist if you are taking, have recently taken or might take any other medicines.

Medicines that may reduce your insulin need (risk of hypoglycaemia):

• Other diabetes medicines
• MAOIs (for depression)
• Beta-blockers (for blood pressure)
• ACE inhibitors
• Salicylates (e.g. aspirin)
• Anabolic steroids
• Sulphonamides (antibiotics)

Medicines that may increase your insulin need (risk of high blood sugar):

• Oral contraceptives
• Thiazide diuretics
• Glucocorticoids ("steroids")
• Thyroid hormones
• Sympathomimetics (e.g. salbutamol)
• Growth hormone
• Danazol

Other important cautions:

• Beta-blockers can mask the warning symptoms of low blood sugar.
• Alcohol may increase or reduce the blood-sugar-lowering effect of insulin.
• Pioglitazone (a type 2 diabetes tablet) combined with insulin has been linked to heart failure in some patients.
• Octreotide/lanreotide may either increase or decrease insulin requirements.

Source: NovoRapid SmPC sections 4.4, 4.5

Pregnancy, Breastfeeding, Driving and Alcohol

Pregnancy: Insulin aspart can be used during pregnancy. Data from two clinical trials (322 and 27 pregnancies) did not indicate any harmful effect of insulin aspart on pregnancy or on the baby's health compared with human insulin. Insulin requirements usually fall in the first trimester, rise during the second and third, and return quickly after delivery. Tight blood glucose control is important. If you are pregnant or planning pregnancy, speak to your diabetes or maternity team.

Breastfeeding: There are no restrictions on using insulin aspart while breastfeeding. It presents no risk to the baby, but your dose may need adjustment. Discuss with your clinician.

Driving: Low blood sugar can impair concentration and reaction times. Take precautions to avoid hypoglycaemia while driving. If you have frequent low blood sugar or find it hard to recognise it, ask your doctor whether you can drive. The leaflet advises always carrying glucose tablets or high-sugar snacks with you.

Alcohol: If you drink alcohol, your need for insulin may change as your blood sugar may either rise or fall. Careful monitoring is recommended.

Sources: NovoRapid SmPC sections 4.6, 4.7, Fiasp SmPC sections 4.6, 4.7, Trurapi SmPC sections 4.6, 4.7, NovoRapid PIL

Missed Doses and Stopping Suddenly

Missed mealtime dose: If you forget to take your insulin, your blood sugar may get too high. Fiasp's product information advises people on basal-bolus treatment who forget a mealtime dose to check their blood glucose to decide whether a dose is needed, then return to their usual schedule at the next meal. Ask your diabetes team what to do for your insulin.

Do not stop insulin suddenly: Stopping insulin without medical advice can cause very high blood sugar and diabetic ketoacidosis, which can be life-threatening. If you are struggling to obtain your usual insulin, contact your GP, diabetes specialist or pharmacist immediately.

Sources: Fiasp SmPC section 4.2, NovoRapid PIL

Monitoring and Check-Ups

Regular monitoring is essential for safe insulin use:

• Blood glucose testing — as advised by your diabetes team, especially when changing dose, during illness, or when starting a new medicine.
• HbA1c — a long-term blood sugar check. For adults with type 2 diabetes, NICE recommends it every 3 to 6 months until it is stable on unchanging treatment, then every 6 months. Your diabetes team will tell you how often you need it.
• Injection sites — check for lumps, thickening or shrinking of fatty tissue. Rotate injection sites within the same body area (abdomen, thigh, upper arm) to reduce lipodystrophy and cutaneous amyloidosis.
• Your diabetes team will tell you which other routine checks you need.
• The product information recommends closer blood glucose monitoring during pregnancy, if you have kidney or liver problems and in older people. Illness, more exercise or a change in diet may mean your dose needs to change. Before travelling across time zones, ask your doctor for advice.

Sources: NICE NG28, NovoRapid SmPC sections 4.2, 4.4, Fiasp SmPC section 4.4

What to Ask a Pharmacist or GP During Supply Issues

If your usual insulin aspart pen or cartridge is unavailable, ask:

1. Which presentations are currently in stock? (e.g. FlexPen vs Penfill vs vial)
2. Can I switch to a biosimilar such as Trurapi? For adults with type 2 diabetes, NICE recommends discussing a possible switch to a lower-cost biosimilar and making a shared decision about it.
3. Do I need a new prescription or device training? Some pens and cartridges need a particular reusable pen or compatible needles, so check with your pharmacist.
4. Should my dose change? When transferring between insulin types or brands, your clinician may need to adjust the dose and monitor you more closely.
5. What should I do if my pump cartridge is unavailable? CPE notes that the mylife YpsoPump Reservoir, which can be self-filled with NovoRapid vials, remains available. Ask your diabetes team what is right for your pump.

Sources: CPE MSNs, NICE NG28 section 1.35.4

Related Medicines a Clinician May Discuss

If insulin aspart is unavailable or unsuitable, your clinician may discuss:

• Other short- or rapid-acting insulins
• Pre-mixed (biphasic) insulins
• Basal insulins given once or twice a day
• For type 2 diabetes, non-insulin medicines such as metformin, SGLT2 inhibitors or GLP-1 receptor agonists (NICE NG28)

Your diabetes team will choose the best option based on your type of diabetes, lifestyle, HbA1c targets and any other health conditions.

Sources: NICE NG28, NovoRapid SmPC section 4.2

Frequently Asked Questions

Is there an insulin aspart shortage in the UK?

Specific presentations have been discontinued or are in limited supply. Fiasp FlexTouch and NovoRapid FlexTouch pre-filled pens have been discontinued. NovoRapid PumpCart is in limited supply until 2027. CPE has listed NovoRapid FlexPen and Penfill (October 2024), NovoRapid vials (June 2025), Fiasp Penfill (March 2024) and Trurapi cartridges (May 2026) as able to support increased demand. Trurapi SoloStar pens had a supply disruption in May–June 2026. Confirm local availability with your pharmacist.

What should I do if my pharmacy cannot get NovoRapid or Fiasp?

Do not stop insulin. Ask your pharmacist which presentations are in stock. Speak to your GP or diabetes team about alternatives such as a different pen, cartridge, vial or biosimilar. Do not change brands or devices without guidance.

Can a pharmacist switch my insulin brand?

Your pharmacist can tell you what is in stock and may contact your prescriber about alternatives. The product information says changing to another type or brand of insulin should be done under strict medical supervision. Any switch should be agreed with your prescriber or diabetes team, with monitoring.

Is NovoRapid FlexTouch discontinued?

Yes. NovoRapid FlexTouch 3 ml pre-filled pens were discontinued from March 2025. CPE listed NovoRapid FlexPen and Penfill as able to support a full increase in demand (October 2024), and FlexPen again in May 2026.

What should pump users do if PumpCart is unavailable?

Pump users should contact their diabetes team urgently. CPE notes that the mylife YpsoPump Reservoir, which can be self-filled with NovoRapid vials, remains available. Do not make pump changes without clinical guidance.

Official Sources and Correction Route

This article is based on:

• CPE Medicine Supply Notifications — MSN/2024/027U, MSN/2024/103, MSN/2025/034
• eMC Summary of Product Characteristics — NovoRapid, Fiasp, Trurapi
• eMC Patient Information Leaflet — NovoRapid PIL
• EMA European Public Assessment Report — NovoRapid EPAR
• NICE Guideline NG28 — Type 2 diabetes in adults: management (updated February 2026)

If you suspect a side effect, report it via the MHRA Yellow Card scheme: https://yellowcard.mhra.gov.uk or search "MHRA Yellow Card" in your app store.

If you spot an error in this article, please contact MediWatch UK so we can correct it.

Sources checked on 27 October 2026. This article is not medical advice.