Lactulose Syrup (Solution IP): Uses, Dose, Side Effects & Brands

Vibcare Pharma

23/10/26

Updated 23 October 2026
Reviewed by Sudhanshu Singhal
16 min read
26 sources

6Vibcare lactulose products, all listed below

1compositions and strengths in the Vibcare range

Brand	Company	Common pack	MRP (Rs)
Looz Oral Solution	Intas Pharmaceuticals Ltd	240 ml	317.52
Livoluk Oral Solution	Panacea Biotec Pharma Ltd	100 ml / 450 ml	129.53 / 583.13
Duphalac Oral Solution Lemon	Abbott	450 ml	594.45
Evict Oral Solution	Albert David Ltd	200 ml	258.30
Emty Oral Solution	Alkem Laboratories Ltd	200 ml	264.60
Swiftolac Syrup	Shreya Life Sciences Pvt Ltd	150 ml	196.88

MRPs as listed on the Indian e-pharmacy pages named under Sources, read 23 October 2026; prices change, so check the pack. Listed in no particular order unless the text says otherwise.

The table lists examples of lactulose oral solution brands shown by Tata 1mg (a large Indian e-pharmacy), read on 23 October 2026. This is not a ranking. 1mg states that MRP may vary by batch, and the price printed on the pack governs.

What is lactulose oral solution / syrup?

Lactulose oral solution is an osmotic laxative — a synthetic sugar that is poorly absorbed, so it reaches the colon unchanged and there draws in water to soften stool and promote bowel movement.

Lactulose is a disaccharide made of galactose and fructose (chemical name D-fructose, 4-O-beta-D-galactopyranosyl; formula C12H22O11). Once it reaches the colon, gut bacteria break it into organic acids that lower the pH of the colon, pull water into the stool, increase stool volume and stimulate bowel movement. This is how it works as a laxative.

In hepatic encephalopathy — the confusion and brain effects that can come with liver disease — the UK Duphalac label attributes the benefit to several actions: suppression of ammonia-forming bacteria in the gut, trapping of ammonia as ammonium ion through acidification of the colon, the laxative effect itself, and altered bacterial use of nitrogen. The US label states that colonic bacteria degrade lactulose, acidifying the colon so that ammonia is trapped as ammonium ion and expelled; 3 per cent or less is excreted in urine.

Strength and forms sold in India

In India lactulose is sold as an oral liquid in which lactulose is the active ingredient. It is commonly labelled Lactulose Solution IP (IP = Indian Pharmacopoeia standard) at 10 g per 15 ml. Some brands print the concentration as 3.335 g per 5 ml (Duphalac), which is the same as 10 g per 15 ml. Always check the strength printed on the product pack.

Indian bottles come in 100 ml, 150 ml, 200 ml, 240 ml and 450 ml packs. In the United States the same product is called Lactulose Solution USP (United States Pharmacopeia standard) and is sold in 118, 237, 473 and 946 ml bottles; in the UK it comes in 15 ml sachets and bottles of 200, 300, 500 and 1000 ml.

Lactulose is the active ingredient; other ingredients and residues depend on the product. The US label states that each 15 ml contains 10 g lactulose with less than 1.6 g galactose, less than 1.2 g lactose and 0.1 g or less fructose, plus colouring agents and purified water. The UK Duphalac label lists no added excipients but carries lactose, galactose, fructose and sulphite residues from manufacture.

What is lactulose oral solution used for?

Lactulose oral solution is used for two conditions as stated on the labels: constipation and hepatic encephalopathy.

The UK Duphalac label lists: (1) treatment of constipation and (2) treatment of hepatic encephalopathy and hepatic coma. The UK Esteve sachet label covers relief of constipation in adults and people aged 7 to 18. The US CONSTULOSE label is for chronic constipation; the US Lactulose Solution USP and ENULOSE labels are for prevention and treatment of portal-systemic encephalopathy, including hepatic pre-coma and coma. So lactulose solution (commonly 10 g per 15 ml) is labelled for different indications in different countries and products.

NHS and MedlinePlus both state that lactulose treats constipation and lowers ammonia in people with liver disease. Indian brand pages on Tata 1mg list both constipation and hepatic encephalopathy. These are the uses stated on labels and by government health sources; no other uses should be assumed.

Dose as stated in the labels

The dose of lactulose depends on the condition being treated and on the age of the patient, and it must always be set by a doctor. The figures below are what each label states; they are not a personal dose instruction.

Constipation

For constipation the following regimens appear on the labels. Always follow the prescription your doctor has written.

Label source	Adults and adolescents	Children
Duphalac SmPC (UK)	Start 15–45 ml daily; maintenance 15–30 ml	7–14 yrs: 15 ml start / 10–15 ml maintenance; 1–6 yrs: 5–10 ml; under 1 yr: up to 5 ml
Esteve sachet SmPC (UK)	Start 15–45 ml (1–3 sachets); maintenance 15–30 ml	7–14 yrs: 15 ml (1 sachet) daily
CONSTULOSE label (US)	15–30 mL daily; may be raised to 60 mL if needed	Safety and effectiveness in children not established

The Duphalac label states that the dose may be taken as a single daily dose or split into two divided doses, ideally at the same time each day (for example at breakfast), and that 1.5 to 2 litres of fluid a day should be drunk. The US CONSTULOSE label notes that 24 to 48 hours may be needed for a normal bowel movement. The NHS advises using the measuring spoon or cup supplied and taking doses at evenly spaced times. The Esteve label advises reducing the dose if diarrhoea occurs.

Hepatic encephalopathy

Label / guideline	Adults	Children
Duphalac SmPC (UK)	Start 30–45 ml three or four times daily; adjust to give two or three soft stools a day	Safety and efficacy in children not established
Rising / ENULOSE label (US)	30–45 mL three or four times daily, adjusted to give two or three soft stools daily	Infants: 2.5–10 mL daily in divided doses; older children: 40–90 mL daily total
ICMR Standard Treatment Workflow (India, for doctors)	20–30 ml every 6 hours, titrated to three or four stools a day	—

The US label notes that hourly 30–45 mL may be used at the start for rapid laxation in adults, and that improvement may occur within 24 hours but may not begin before 48 hours. The ICMR workflow is an advisory for doctors treating encephalopathy in acute-on-chronic liver failure. For children, the US label says very little paediatric information is available and diarrhoea should lead to an immediate dose reduction.

General timing and food rules

The NHS states that lactulose can be taken with or without food, at the same times each day, evenly spaced, and that squash may be added for flavour. The Duphalac label states the dose may be taken diluted or undiluted, with water or fruit juice. A missed dose should simply be skipped — do not double up. Pharmacy-bought lactulose in the UK is for people aged 14 and over; babies and younger children should only receive it on a doctor's prescription.

Side effects of lactulose

The reported frequency of side effects varies between products and labels; serious reactions have been reported but their frequency is often not known.

Common side effects

According to the UK Duphalac SmPC: very common (1 in 10 or more) — diarrhoea; common (1 in 100 to under 1 in 10) — flatulence, abdominal pain, nausea and vomiting. The UK Esteve sachet label lists flatulence and abdominal pain as very common, and nausea and vomiting as common. US labels report gaseous distention, flatulence, belching and abdominal discomfort in about 20 per cent of patients, and note that precise frequency data are not available.

Flatulence often occurs in the first days and usually settles after a couple of days. Taking more than the prescribed dose can cause abdominal pain and diarrhoea; the dose should then be reduced. Long, high-dose use (usually in hepatic encephalopathy) may lead to electrolyte imbalance.

Serious side effects — seek urgent medical help

Allergic reaction (anaphylaxis): swollen throat or tongue, raised itchy rash, difficulty breathing. Seek emergency care immediately.
Low potassium from frequent diarrhoea after long or excessive use: muscle weakness, tiredness, frequent urination, irregular heartbeat.
Severe stomach pain or cramps with vomiting: stop the medicine and call the doctor at once (MedlinePlus).
Infants may develop low sodium and dehydration (US label). Patients with serious liver disease may have low potassium needing other treatment.

The UK Duphalac label also lists itching (pruritus) as a reported reaction of unknown frequency.

In case of overdose, the UK Duphalac label lists diarrhoea, loss of electrolytes and abdominal pain; the treatment is to stop or reduce the dose and replace electrolytes if fluid loss is large. There is no specific antidote.

Who should not take lactulose, and drug interactions

Lactulose should not be taken by people who are allergic to it, have galactosaemia or a bowel obstruction; several drug interactions are also described on the labels.

Contraindications

Hypersensitivity to lactulose or any excipient (UK Duphalac SmPC).
Galactosaemia (UK Duphalac SmPC).
Gastro-intestinal obstruction, perforation or risk of perforation (UK Duphalac SmPC). The Esteve sachet label adds acute inflammatory bowel disease and painful abdominal conditions of unknown cause.
Patients who need a low-galactose diet (US labels — the product contains galactose).
Rare hereditary galactose or fructose problems, total lactase deficiency or glucose-galactose malabsorption — do not take (UK SmPC).

The NHS adds that lactulose may not suit people with lactose intolerance, galactose or fructose intolerance, irritable bowel syndrome, diverticular disease, Crohn's disease, or a bowel blockage not caused by constipation. Undiagnosed painful abdominal symptoms must be assessed by a doctor before starting treatment.

Drug interactions

The UK Duphalac SmPC states that no interaction studies have been performed. The UK Esteve sachet label and the US labels describe the following interactions:

Interacting medicine or group	Effect stated on the label
Thiazides, corticosteroids, amphotericin B	May increase potassium loss caused by these drugs
Cardiac glycosides (e.g. digoxin)	Potassium deficiency may raise the glycoside effect
Mesalazine / 5-ASA (pH-dependent release tablets)	May be inactivated by colonic acidification; the mesalazine product SmPC advises not to combine
Neomycin and other oral anti-infectives	May interfere with the bacterial breakdown of lactulose
Non-absorbable antacids	May inhibit the pH drop in the colon
Other laxatives	Should not be used together, especially early in treatment, because loose stools may falsely suggest the dose is enough

MedlinePlus advises telling the doctor about antacids, neomycin and other laxatives before starting them, and before surgery or tests on the colon or rectum.

Pregnancy and breastfeeding

The UK Duphalac SmPC states that no effects are anticipated during pregnancy because systemic exposure is negligible, and that lactulose can be used in pregnancy and breastfeeding. The NHS agrees but advises speaking to a pharmacist or doctor first; serious effects in breastfed babies are rare. The older US label says use only if clearly needed and advises caution during breastfeeding. Always ask your doctor before taking any medicine during pregnancy.

Children

The UK SmPC states that laxatives in children should be used only exceptionally and under medical supervision, though it does give constipation doses from under 1 year upwards. The NHS says children under 14 should take lactulose only if prescribed. US labels for constipation have no paediatric dose and say safety in children is not established. The US hepatic encephalopathy label notes that infants may develop low sodium and dehydration.

Diabetes, alcohol and driving

The UK SmPC says the constipation dose should not pose a problem for people with diabetes; the much higher hepatic encephalopathy dose may need to be considered. US labels advise caution in diabetics because of the galactose and lactose content. NHS notes that high doses used in hepatic encephalopathy can affect blood glucose. The solution contains small amounts of other sugars (galactose, lactose, fructose) per 15 ml, as stated on the US label.

On alcohol, the NHS states that you can eat and drink as normal while taking lactulose, including alcohol, as long as you drink enough fluid. The UK SmPC states that lactulose has no or negligible effect on the ability to drive or use machines.

Elderly or debilitated patients who use lactulose for more than six months should have blood electrolytes (potassium, chloride, carbon dioxide) checked periodically, according to the US Kristalose label.

Rules in India for lactulose

Lactulose oral solution is listed in India's National List of Essential Medicines (NLEM) 2022 and is therefore price-controlled by the NPPA; it is not named in Schedules H, H1, G or X of the Drugs and Cosmetics Rules as read up to 30 September 2020.

Schedule status

The consolidated Drugs and Cosmetics Rules, 1945 (as amended up to 30 September 2020) were searched in full and "lactulose" does not appear in Schedule H, H1, G or X in that version. The Rules do not define a separate OTC sale category. Whether later amendments have changed this status could not be confirmed from a primary source. Use lactulose under a doctor's guidance.

NLEM 2022 and price control

NLEM 2022 (Schedule I of the DPCO 2013, S.O. 5249(E) dated 11 November 2022) lists lactulose twice: at entry 17.5.3 (Laxatives), oral liquid 10 g/15 mL, healthcare level S,T; and at entry 7.4.8 (Palliative care), oral liquid 10 g/15 mL, S,T. Because the 10 g/15 ml oral liquid is NLEM-listed, the NPPA fixes a ceiling price per ml.

The historical official ceiling (NLEM 2015 list, updated 13 August 2018) was ₹1.03 per ml with effect from 2 April 2018. A secondary source (Counterfoil) reports a revised ceiling of ₹1.26 per ml under S.O. 1575(E) dated 25 March 2026, with the revision taking effect from 1 April 2026 and exclusive of GST.

Lactulose brands listed by Tata 1mg

The table at the top of this page lists examples of lactulose oral solution brands shown by Tata 1mg on 23 October 2026, with their marketers, pack sizes and MRPs. No sales ranking is claimed. Note that Lactihep Syrup (Sun Pharma) contains lactitol, not lactulose, and is not a lactulose brand.

The Vibcare lactulose range

Vibcare Pharma markets lactulose oral solution (10 g per 15 ml) in 100 ml and 200 ml bottles across four of its divisions: Laxijem (Auspin division), Laxivib (Prima division), Laxoto (Medanor division) and Vivolac (Evermed division), giving franchise partners a choice of pack sizes and brand names for their local market.

Lactulose 10 Gm

4 divisions

Laxijem 100ML SolutionAuspin · 100ml₹132.3
Laxijem 200ML SolutionAuspin · 200ml₹264.6
Laxivib 100ML SolutionPrima · 100ml₹132.3
Laxivib 200ML SolutionPrima · 200ml₹264.6
Laxoto 200ML SolutionMedanor · 200ml₹258
Vivolac SolutionEvermed · 200ml₹264.6

The full lactulose range is available to Vibcare PCD franchise partners with monopoly rights in their district; see our Gastro PCD franchise and PCD pharma franchise pages.

For distributors and entrepreneurs

Add lactulose to your range

Vibcare appoints one PCD franchise partner per district, with monopoly rights confirmed in writing. Trade rates for every product are on its product page.

Enquire about a PCD franchise Chat on WhatsApp

Frequently asked questions

What is lactulose syrup used for?

Lactulose syrup (Lactulose Solution IP, 10 g per 15 ml) is used to treat constipation and hepatic encephalopathy — the confusion that can arise when ammonia builds up in the blood of people with liver disease. It is an osmotic laxative that softens stool by drawing water into the bowel. Both the NHS and the UK Duphalac label state these two uses; some US labels list only one of the two.

What is the use of lactulose solution IP?

"IP" marks the Indian Pharmacopoeia quality standard for the product; it does not change its use. Lactulose Solution IP is used for the same two conditions — constipation and hepatic encephalopathy — as stated on Indian brand pages and in international labels. The IPC draft monograph gives the usual strength as 10 g per 15 ml. Always use it as prescribed by a doctor.

How much is 20 grams of lactulose in mL?

At the standard concentration of 10 g per 15 ml, 20 g of lactulose equals 30 ml. This is a simple arithmetic conversion (20 ÷ 10 × 15). The US label cross-checks this: it states that 30–45 mL contains 20–30 g of lactulose. This conversion applies only to the oral solution, not to crystal or powder products such as Kristalose, which are dosed differently.

How many mL is 1 bottle of lactulose?

It depends on the pack size. Indian lactulose bottles are sold in 100 ml, 150 ml, 200 ml, 240 ml and 450 ml sizes. For example, a 100 ml bottle at 10 g per 15 ml holds about 66.7 g of lactulose (about six full 15 ml measures plus 10 ml), and a 200 ml bottle holds about 133 g. In other countries, UK bottles go up to 1000 ml and US bottles up to 946 mL.

What are the potential drug interactions with lactulose?

Lactulose may interact with several medicines. The UK sachet label warns of increased potassium loss with thiazides, corticosteroids and amphotericin B; raised cardiac glycoside effect when potassium is low; and inactivation of pH-dependent drugs such as mesalazine. The US label adds that neomycin and other oral anti-infectives may interfere with lactulose breakdown, non-absorbable antacids may inhibit the pH drop in the colon, and other laxatives should not be used together. Tell your doctor about every medicine you take before starting lactulose.

Is lactulose used for constipation?

Yes. Constipation is the first indication listed on the UK Duphalac label, and both the NHS and MedlinePlus state that lactulose treats constipation. The US CONSTULOSE label is for chronic constipation. Onset of action is stated as 2 to 3 days in the UK and 24 to 48 hours in the US. It must be used as prescribed by a doctor.

Is lactulose safe in pregnancy and for children?

Pregnancy: the UK label says lactulose can be used during pregnancy and breastfeeding because systemic exposure is negligible; the NHS advises speaking to a pharmacist or doctor first; the US label says use only if clearly needed. Children: the UK label gives constipation doses from under 1 year but says laxatives in children should be exceptional and under medical supervision; the NHS says children under 14 should take it only if prescribed. In all cases, follow your doctor's advice.

How long does lactulose take to work?

For constipation, the NHS states it can take 2 to 3 days, and the UK label says several days (2–3) may be needed; the US constipation label states 24 to 48 hours. For hepatic encephalopathy, the US label states improvement may occur within 24 hours but may not begin before 48 hours. If there is no improvement after 3 days, see your doctor (NHS).

Does lactulose increase blood sugar?

Lactulose itself is poorly absorbed (the US label states that 3 per cent or less is excreted in urine, and the UK SmPC describes systemic exposure as negligible), but the solution contains small amounts of other sugars — galactose, lactose and fructose per 15 ml as stated on the US label. The UK SmPC says the constipation dose should not pose a problem for diabetics, while the much higher hepatic encephalopathy dose may need to be considered; US labels advise caution in diabetics. No label read states that lactulose itself raises blood glucose.

Sources

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