Insulin lispro (Humalog)

Pronunciation: IN-suh-lin LIS-pro.

Generic name
insulin lispro
Drug class
Rapid-acting insulin analogue (antidiabetic agent)
Form
Solution for injection: vial, cartridge, prefilled pen (KwikPen), 100 units/mL and 200 units/mL
Route
Subcutaneous injection (or intravenous, in a clinical setting)
Legal status
Prescription-only

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Humalog (5) · Full directory

What insulin lispro is and how it works

Insulin lispro is a rapid-acting insulin analogue used by adults and children with diabetes mellitus to help control blood glucose (sugar) levels. It is injected under the skin, usually shortly before a meal, and starts working faster than regular human insulin. (1) (2)

Insulin lispro helps your body move glucose from the blood into cells for energy, closely mimicking the natural, fast insulin response to a meal. It is prescribed and dosed individually by a clinician, and its rapid onset means timing around meals matters. It carries genuine, serious warnings about low blood sugar (hypoglycaemia), low blood potassium (hypokalaemia), and about never sharing insulin delivery devices between people.

Mechanism of action: how insulin lispro works

Insulin lispro ([Lys(B28), Pro(B29)] human insulin analogue) differs from human insulin by a small structural change that reduces self-association, allowing faster absorption from the subcutaneous injection site and a more rapid onset and shorter duration of action than regular human insulin. (1) (3)

What insulin lispro is used for

Glycaemic control in diabetes mellitus

Used to improve blood glucose control in adults and children with diabetes mellitus, including at diagnosis, as part of an insulin regimen individualised by a clinician. (1) (2) (3)

Before taking insulin lispro

Do not take / not appropriate for

  • Do not use insulin lispro during an episode of hypoglycaemia (low blood sugar). (all countries where authorised) (1)
  • Do not use if you have had a serious allergic reaction to insulin lispro or any of its ingredients. (all countries where authorised) (1)

Tell your clinician about

  • Any history of severe or frequent low blood sugar (hypoglycaemia), or reduced awareness of hypoglycaemia symptoms.
  • Any kidney or liver problems, which can affect how much insulin you need.
  • Any heart problems, especially if you also take a PPAR-gamma agonist medicine (a class of diabetes tablets), since fluid retention and heart failure have been reported with combined use.
  • If you use an insulin pump, and how to recognise and respond to pump malfunction (which can lead to high blood sugar and ketoacidosis).
  • All other medicines you take, since many can affect blood sugar control.
  • Whether you are pregnant, planning pregnancy, or breastfeeding.
  • Which specific Humalog product and strength you have been prescribed, since mix-ups between different Humalog products/strengths have been reported.
(1) (6)

How to take insulin lispro

  • Inject under the skin (subcutaneously) in the abdomen, thigh, or another site advised by your clinician, usually shortly before a meal because of its fast onset of action.
  • Rotate injection sites (do not use exactly the same spot more than about once a month) to reduce the risk of skin changes at the injection site.
  • NEVER share prefilled pens, cartridges, or reusable pens with another person, even if you change the needle. If you use vials, NEVER share needles or syringes with another person. Sharing carries a real risk of transmitting blood-borne infections such as hepatitis or HIV.
  • Only your clinician should change your insulin dose, brand, or regimen -- do not switch products or adjust your dose yourself.
  • Always check you have the correct Humalog product and strength before injecting.
(1) (2)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

Contact your prescriber or diabetes care team for individual guidance on a missed dose, since timing relative to meals and blood glucose matters, and never take an extra dose to make up for a missed one without specific instructions.

Overdose

Seek urgent medical attention if you think you have taken too much insulin lispro, or if you develop signs of severe low blood sugar (confusion, sweating, shakiness, difficulty speaking, seizures, or loss of consciousness) -- follow your emergency hypoglycaemia plan and treat low blood sugar promptly as advised by your clinician. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Low blood sugar (hypoglycaemia) -- the most common side effect of any insulin.

What to notice: Low blood sugar (hypoglycaemia) -- the most common side effect of any insulin.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Injection site reactions (redness, swelling, itching).

What to notice: Injection site reactions (redness, swelling, itching).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (2)

Weight gain.

What to notice: Weight gain.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (2)

Skin changes at frequently-used injection sites (lipodystrophy) if sites are not rotated.

What to notice: Skin changes at frequently-used injection sites (lipodystrophy) if sites are not rotated.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (6)

Serious warnings

Signs of severe low blood sugar (hypoglycaemia) — emergency

Symptoms: Confusion, sweating, shaking, rapid heartbeat, difficulty speaking, seizures, or loss of consciousness.

Action: Treat promptly following your clinician's hypoglycaemia action plan, and seek emergency medical help immediately for severe symptoms or loss of consciousness -- hypoglycaemia is the most common adverse reaction of insulin therapy and can be life-threatening or fatal. (1) (2)

Sharing insulin delivery devices — high caution

Symptoms: Not applicable -- this is a preventable risk, not a symptom to watch for.

Action: Never share prefilled pens, cartridges, or reusable pens with another person, even if the needle is changed. Never share needles or syringes if using vials. Sharing carries a genuine risk of transmitting blood-borne infections such as hepatitis viruses or HIV, even when the needle itself is changed. (1) (2)

Signs of low blood potassium (hypokalaemia) — high caution

Symptoms: Muscle weakness, abnormal heart rhythm, or breathing difficulty.

Action: Contact your clinician promptly or seek emergency help for severe symptoms -- all insulins, including this one, shift potassium into cells and can cause hypokalaemia, which if untreated may cause respiratory paralysis, dangerous heart rhythms, and death, especially in at-risk patients. (1)

Signs of a serious allergic reaction — emergency

Symptoms: Widespread rash, swelling of the face/throat, difficulty breathing, or a rapid drop in blood pressure.

Action: Seek emergency medical help immediately -- severe, generalised allergy, including anaphylaxis, has been reported with insulins including this one. (1)

Signs of high blood sugar or ketoacidosis (insulin pump users) — high caution

Symptoms: Very high blood sugar readings, nausea, vomiting, abdominal pain, fruity-smelling breath, or rapid breathing.

Action: Contact your clinician or seek emergency help promptly -- pump malfunction can cause rapid-onset hyperglycaemia and ketoacidosis in insulin pump users. (1)

Interactions

  • Many other medicines can affect blood glucose control (raise or lower insulin needs), including some diabetes tablets, certain heart/blood pressure medicines, and steroids -- tell your clinician about all medicines you take so your insulin dose can be adjusted appropriately. (1)
  • PPAR-gamma agonist diabetes tablets (thiazolidinediones) combined with insulin can cause fluid retention and heart failure, particularly in patients with existing heart problems. (1)
  • Alcohol can affect blood glucose control and increase the risk of hypoglycaemia. (2)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Insulin requirements often change during pregnancy; insulin lispro can be used under close clinician supervision with individualised dose adjustment throughout pregnancy. (1) (2) (3) (4) (5) (6)

Breastfeeding

Insulin requirements may change during breastfeeding; use under clinician guidance with monitoring and dose adjustment as needed. (1) (2) (3) (4) (5) (6)

Children

Approved for use in paediatric patients with diabetes mellitus; dosing individualised by a paediatric diabetes specialist. (1) (2) (3) (4) (5) (6)

Elderly

No specific restriction described in the sources reviewed, but hypoglycaemia risk and ability to recognise/manage it should be considered individually. (1) (2) (3) (4) (5) (6)

Hepatic_impairment

May affect insulin requirements; individualised monitoring and dose adjustment by a clinician. (1) (2) (3) (4) (5) (6)

Renal_impairment

May affect insulin requirements; individualised monitoring and dose adjustment by a clinician. (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Baseline blood glucose control (e.g. HbA1c)
  • Kidney and liver function if relevant
  • Personal history of hypoglycaemia awareness/severity
  • Cardiac status if using with a PPAR-gamma agonist

During treatment

  • Regular self-monitoring of blood glucose as directed by your clinician.
  • Prompt recognition and treatment of hypoglycaemia; carry a fast-acting source of sugar.
  • Periodic review of injection sites for signs of skin changes.
  • Monitoring for signs of hypokalaemia in at-risk patients.
  • Insulin pump users: monitoring for signs of pump malfunction and resulting hyperglycaemia/ketoacidosis.
(1)

Storage

Store unopened Humalog in a refrigerator (2-8C); do not freeze or expose to excessive heat or direct sunlight. Once in use, vials, cartridges, and prefilled pens can be kept at room temperature (below 30C, away from heat and light) and should be discarded after 28 days.

Professional information

Clinician-facing context only, sourced from the current US prescribing information and UK SmPC; verify against the current full label before prescribing.

United States, United Kingdom, European Union, Canada, Australia, New Zealand

Indication: Glycaemic control in adult and paediatric patients with diabetes mellitus

Dose summary: Individualised subcutaneous dosing based on blood glucose monitoring, meal content, and activity; given close to mealtime (within about 15 minutes before eating) due to rapid onset. Can also be given intravenously in a clinical/monitored setting or via insulin pump.

Renal context: Insulin requirements may be reduced in renal impairment; monitor closely and adjust dose individually. (1) (4)

Mechanism of action

Hepatic guidance

Insulin requirements may be altered in hepatic impairment; individualise and monitor.

Overdose note

Manage hypoglycaemia per standard protocol (oral carbohydrate for mild/moderate cases; glucagon or IV glucose for severe cases/loss of consciousness), with close monitoring for hypokalaemia; no specific antidote beyond glucose/glucagon and supportive care. (1) (3)

Frequently asked questions

Can I share my Humalog (insulin lispro) pen with a family member if I change the needle?

No. The current US and UK labels are explicit and firm: prefilled pens, cartridges, and reusable pens must never be shared between patients, even if the needle is changed. If you use vials, needles and syringes must never be shared either. This is because sharing carries a real risk of transmitting blood-borne infections such as hepatitis viruses or HIV -- changing only the needle does not remove this risk, since the device itself can still carry contamination from contact with the previous user's skin or blood. (1) (2)

Does insulin lispro (Humalog) affect my potassium levels?

Yes. All insulins, including Humalog, cause potassium to shift from outside cells to inside cells, which can lower blood potassium levels (hypokalaemia). If this goes untreated, it can cause muscle weakness, dangerous heart rhythm problems, breathing difficulty, and in serious cases can be life-threatening. This risk is higher in certain situations, so your clinician may monitor your potassium levels, especially if you have other risk factors. (1)

What are the signs of low blood sugar (hypoglycaemia) with Humalog, and why is it taken seriously?

Hypoglycaemia is the most common side effect of insulin, including Humalog. Severe hypoglycaemia can cause seizures, and can be life-threatening. Know your own early warning signs (such as shakiness, sweating, confusion, or hunger), carry a fast-acting sugar source, and make sure people close to you know how to help if you become severely hypoglycaemic. (1)

What is the mechanism of action of insulin lispro?

Insulin lispro ([Lys(B28), Pro(B29)] human insulin analogue) differs from human insulin by a small structural change that reduces self-association, allowing faster absorption from the subcutaneous injection site and a more rapid onset and shorter duration of action than regular human insulin. (1) (3)

What is the generic name of Insulin lispro (Humalog)?

The generic name is insulin lispro. (1) (3)

What class of drug is insulin lispro?

Insulin lispro (Humalog) is classed as: Rapid-acting insulin analogue (antidiabetic agent). (1) (3)

References

  1. HUMALOG (insulin lispro injection) -- full prescribing information (Revised 1/2026)U.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, Eli Lilly and Company · United States · accessed 2026-07-30 · source 1
  2. Humalog 100 units/ml, solution for injection in vial -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Eli Lilly and Company Limited · United Kingdom · accessed 2026-07-30 · source 2
  3. Humalog (insulin lispro) -- EPAR medicine overviewEuropean Medicines Agency (EMA) -- EPAR for Humalog · European Union · accessed 2026-07-30 · source 3
  4. HUMALOG (insulin lispro injection) -- Product MonographHealth Canada product monograph, Eli Lilly Canada Inc. · Canada · accessed 2026-07-30 · source 4
  5. HUMALOG insulin lispro -- multiple ARTG entries (cartridge 53466, vial 53488, KwikPen 64214, U200 KwikPen 226893, Mix25/Mix50 69163/69166/69167)Therapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-30 · source 5
  6. HUMALOG (insulin lispro) -- New Zealand Data SheetMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-30 · source 6

Brand names by country

Single-ingredient insulin lispro names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Humalog100 [iU]/mL, 200 [iU]/mL · a-s medication solutions
  • LYUMJEV100 [iU]/mL, 200 [iU]/mL · eli lilly and company
  • ADMELOG100 U/mL · sanofi-aventis u.s. llc
  • Humalog Mix75/25100 [iU]/mL · eli lilly and company
  • Humalog Mix50/50 KwikPen100 [iU]/mL · eli lilly and company
  • Humalog Tempo Pen100 [iU]/mL · eli lilly and company
  • LYUMJEV Tempo Pen100 [iU]/mL · eli lilly and company
  • Insulin Lispro Protamine and Insulin Lispro Injectable Suspension Mix75/25 KwikPen100 [iU]/mL · eli lilly and company

United Kingdom

  • Humalog (2)MHRA licensed emc smpc confirmed · 100 units/ml, 200 units/ml · Eli Lilly and Company Limited

Canada

  • HUMALOG

Australia

  • Humalog (5)TGA ARTG multiple entries registered since 1996 · Eli Lilly Australia Pty Ltd

New Zealand

  • Humalog (6)medsafe data sheet confirmed · 100 units/mL · Eli Lilly (NZ) Limited · Medsafe has issued a real medication-error safety communication about confusion between different Humalog products/strengths -- worth flagging for patient safety.
View brands in additional countries.

European Union

Humalog (3)

This page provides general reference information about insulin lispro (Humalog) and is not a substitute for advice from the clinician managing your diabetes care. Never share insulin delivery devices with another person, even if the needle is changed.

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