Sweet violet (Viola odorata)

Q: Does sweet violet help sleep?

Small Iranian trials and a 5-trial meta-analysis found better sleep-quality scores than placebo, using syrup or nasal oil for about a month. Sleep latency and efficiency did not improve significantly in the pooled analysis.

Q: Does violet syrup help a cough?

Added to usual care, it shortened time to cough relief in children with intermittent asthma and eased cough in adult COVID-19 outpatients.

Q: Does sweet violet interact with medicines?

Unknown. No drug-interaction study or case report was found, and the trials do not describe testing it with sleep medicines, blood thinners or other drugs. NCCIH notes that supplements can interact with medicines.

Q: Is sweet violet the same as African violet?

No. Sweet violet is Viola odorata; African violets are unrelated houseplants (Saintpaulia).

Q: How is violet oil used for sleep?

In the trials, a few drops of violet extract in almond or sesame oil were placed in each nostril nightly. Placebo drops also improved sleep, though less.

Q: How strong is the evidence?

Low to moderate: trials are small, short, mostly from Iran, and mix different forms and doses.

Also called Viola odorata, violet flower, violet syrup, violet oil, banafsheh, English violet.

Best grade C across 9 graded outcomes Botanical Last checked Oct 21, 2026

The short answer

From 11 sources

Sweet violet is a flowering herb from Persian medicine, tested as an oral syrup and as nasal or skin oil. Small Iranian trials report better sleep scores in insomnia and menopause, faster cough relief added to usual care, and single trials of the oil for dry eye and dialysis itch. Trials are short and doses vary.

Every graded outcome on this page

9 rows · line = participants

Grade CInsomnia scores across trialsSleepn 224
Grade CCough in children with intermittent asthma (add-on)Coughn 182
Grade CCOVID-19 symptoms in outpatients (add-on)Coughn 108
Grade CSleep quality in menopausal womenSleepn 84
Grade CInsomnia in people with depression or OCD (add-on)Sleepn 83
Grade DDry eye: tear production and symptoms (nasal violet oil)Violet extract in almond oil, nasal dropsn 91
Grade DChronic insomnia (nasal violet oil)Sleepn 75
Grade DItch and dry skin in hemodialysis (topical oil with massage)Violet oil applied with massagen 57
Grade DFever in children with neutropenia (topical oil)Fevern 41
6 more graded outcomes, in the evidence chapter

Key facts

Sleep, menopause: Violet syrup 5 mL twice daily for a month cut PSQI scores from 9.2 to 4.9 vs 8.4 to 8.1 with placebo in 84 women¹
Insomnia overall: A meta-analysis of 5 trials (224 people) found PSQI 4.67 points better than placebo⁷
Cough in children: Added to standard asthma care, violet syrup shortened time to cough relief in 182 children⁴
Forms differ: Sleep trials used both oral syrup and nasal oil drops; results from one do not transfer to the other^1,3

What it is

Sweet violet (Viola odorata) is a flowering plant used in Persian medicine as a syrup for sleep and cough and as an oil for nasal drops.

How it works

Proposed

How sweet violet affects sleep or cough is not established in humans. Trial authors cite traditional Persian use and laboratory anti-inflammatory and antitussive activity; no human mechanism studies were found.⁶

Forms, side by side

3 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.

Sweet violet (Viola odorata) forms compared

3 forms

Sweet violet (Viola odorata) forms compared: 3 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
3 forms	Violet flower syrup (oral)	Violet oil nasal drops (extract in almond or sesame oil)	Violet oil applied to the skin
Absorption in people	Not reported.^1,2,4,6	Not reported.^3,8	Not reported.^5,11
GI tolerance	No serious problems described in 1-month trials.^1,2,4,6	Some mild complaints and no serious adverse events in a 50-person study.^3,8	Not reported in the trial abstracts.^5,11
Studied for	Sleep, cough	Insomnia; dry eye (one trial)	Fever in children (single application, in hospital); itch in hemodialysis (with massage)

Violet flower syrup (oral)
Absorption in people
Not reported.^1,2,4,6
GI tolerance
No serious problems described in 1-month trials.^1,2,4,6
Studied for
Sleep, cough
Violet oil nasal drops (extract in almond or sesame oil)
Absorption in people
Not reported.^3,8
GI tolerance
Some mild complaints and no serious adverse events in a 50-person study.^3,8
Studied for
Insomnia; dry eye (one trial)
Violet oil applied to the skin
Absorption in people
Not reported.^5,11
GI tolerance
Not reported in the trial abstracts.^5,11
Studied for
Fever in children (single application, in hospital); itch in hemodialysis (with massage)

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

9 graded outcomes, largest study first

All 9 graded outcomes found an improvement. The largest, a 2022 meta-analysis of 224 people on insomnia scores across trials, found an improvement.

By sizeTable

1Insomnia scores across trials

Improved · Grade C · Meta-analysis, 224 people, 2022

Adults with chronic insomnia (5 trials)

Dose, result and source

Every graded outcome on this page, largest study first
Outcome	Found	People	Study	Who was studied
Insomnia scores across trials	Improved	224	Grade C · Meta-analysis, 2022	Adults with chronic insomnia (5 trials)
Cough in children with intermittent asthma (add-on)	Improved	182	Grade C · RCT, 2015	Children aged 2-12 with intermittent asthma (Iran)
COVID-19 symptoms in outpatients (add-on)	Improved	108	Grade C · RCT, 2023	Adult COVID-19 outpatients (Isfahan, Iran)
Dry eye: tear production and symptoms (nasal violet oil)	Improved	91	Grade D · RCT, 2019	Adults aged 18–60 with dry eye symptoms
Sleep quality in menopausal women	Improved	84	Grade C · RCT, 2024	Menopausal women (Mashhad, Iran)
Insomnia in people with depression or OCD (add-on)	Improved	83	Grade C · Pilot RCT, 2020	Adults with mild-moderate depression (40) or OCD (43) and insomnia (Tehran, Iran)
Chronic insomnia (nasal violet oil)	Improved	75	Grade D · RCT, 2018	Adults with chronic insomnia (Mashhad, Iran)
Itch and dry skin in hemodialysis (topical oil with massage)	Improved	57	Grade D · RCT, 2019	Hemodialysis patients with uremic pruritus
Fever in children with neutropenia (topical oil)	Improved	41	Grade D · RCT, 2020	Febrile neutropenic children in hospital (Shiraz, Iran)

Every graded row

9 rows

Form tested

Showing 9 of 9 outcomes. Human trials only.

Grade CInsomnia scores across trialsSleepPSQI -4.67 vs placeboMeta-analysis · 5 studies
n 224 · 2022

Improved Total PSQI improved by 4.67 points and ISI by 6.30 points vs placebo; sleep latency, efficiency and daytime dysfunction did not differ significantly.

Design: Meta-analysis, 5 studies, n = 224, 2022
Population: Adults with chronic insomnia (5 trials)
Form: Viola odorata preparations (syrup or nasal oil)
Dose: Varied by trial
Duration: About 1 month
Source: Reference 7 · PubMed 35734476 (opens PubMed)

Grade CCough in children with intermittent asthma (add-on)CoughFaster cough reliefRCT
n 182 · 2015

Improved Time to a 50% cough reduction and to full cough suppression was shorter with violet syrup (P = .001 and < .001).

Design: RCT, n = 182, 2015
Population: Children aged 2-12 with intermittent asthma (Iran)
Form: Violet flower syrup vs placebo, with a short-acting beta-agonist
Dose: Dose not stated in the abstract
Duration: Until cough resolved
Source: Reference 4 · PubMed 25954025 (opens PubMed)

Grade CCOVID-19 symptoms in outpatients (add-on)CoughFaster symptom reliefRCT
n 108 · 2023

Improved All symptoms improved in both groups; cough (P = 0.025), muscle pain, headache and diarrhoea fell more with violet syrup.

Design: RCT, n = 108, 2023
Population: Adult COVID-19 outpatients (Isfahan, Iran)
Form: Violet syrup vs placebo syrup, added to usual care
Dose: Dose not stated in the abstract
Duration: 7 days
Source: Reference 6 · PubMed 36535329 (opens PubMed)

Grade CSleep quality in menopausal womenSleepPSQI about 3 points betterRCT
n 84 · 2024

Improved PSQI sleep score fell from 9.2 to 4.9 with violet syrup vs 8.4 to 8.1 with placebo (P < 0.001).

Design: RCT, n = 84, 2024
Population: Menopausal women (Mashhad, Iran)
Form: Viola odorata syrup vs placebo syrup
Dose: 5 mL twice daily
Duration: 1 month
Source: Reference 1 · PubMed 38177831 (opens PubMed)

Grade CInsomnia in people with depression or OCD (add-on)SleepBetter sleep scoresPilot RCT
n 83 · 2020

Improved Total PSQI improved vs placebo in both the depression and OCD arms (p < 0.001); depression (BDI-II) and OCD (Y-BOCS) scores also improved.

Design: Pilot RCT, n = 83, 2020
Population: Adults with mild-moderate depression (40) or OCD (43) and insomnia (Tehran, Iran)
Form: Viola odorata syrup vs placebo syrup, added to usual treatment
Dose: 5 mL every 12 hours
Duration: 4 weeks
Source: Reference 2 · PubMed 32073874 (opens PubMed)

Grade DDry eye: tear production and symptoms (nasal violet oil)Healthy agingImprovedRCT
n 91 · 2019

Improved Schirmer tear test, tear breakup time and the Ocular Surface Disease Index improved more with violet-almond oil than with almond oil alone or placebo (p < 0.05); Oxford staining grade did not differ.

Design: RCT, n = 91, 2019
Population: Adults aged 18–60 with dry eye symptoms
Form: Violet extract in almond oil, nasal drops
Dose: 2 drops three times daily
Duration: 1 month
Source: Reference 10 · PubMed 31060104 (opens PubMed)

Grade DChronic insomnia (nasal violet oil)SleepLargest sleep-score gain of three armsRCT
n 75 · 2018

Improved Insomnia Severity Index and PSQI improved in all three groups; the violet oil group improved most (between-group P < 0.002 and < 0.001).

Design: RCT, n = 75, 2018
Population: Adults with chronic insomnia (Mashhad, Iran)
Form: Violet oil nasal drops vs almond oil vs placebo drops
Dose: 3 drops per nostril nightly
Duration: 30 days
Source: Reference 3 · PubMed 29217495 (opens PubMed)

Grade DItch and dry skin in hemodialysis (topical oil with massage)Hair & skinImprovedRCT
n 57 · 2019

Improved Both groups improved; massage with violet oil reduced skin dryness and itch severity, location and frequency more than massage alone.

Design: RCT, n = 57, 2019
Population: Hemodialysis patients with uremic pruritus
Form: Violet oil applied with massage
Dose: 5 mL per 7-minute massage session
Duration: 6 sessions over 2 weeks
Source: Reference 11 · PubMed 31331569 (opens PubMed)

Grade DFever in children with neutropenia (topical oil)FeverFewer rescue paracetamol dosesRCT
n 41 · 2020

Improved Temperature fell at 30 minutes with violet oil but not placebo; fewer children needed rescue paracetamol (5 vs 17).

Design: RCT, n = 41, 2020
Population: Febrile neutropenic children in hospital (Shiraz, Iran)
Form: Viola odorata oil rubbed around the navel vs placebo
Dose: 20 drops topically
Duration: Single application, followed 4 hours
Source: Reference 5 · PubMed 31250761 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

Menopause trial: about a 4-point gap

PSQI fell 4.3 points with violet syrup and 0.3 points with placebo, a difference of about 4 points over one month.¹

Better scores, not faster sleep

Pooled across 224 people, overall sleep-quality and insomnia scores improved, but sleep latency, sleep efficiency and daytime function did not differ from placebo.⁷

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from 5 mL of violet syrup twice daily for 1-4 weeks to 2-3 nasal drops of violet oil per nostril nightly, or 2 drops three times daily, for a month; skin oil was used as 20 drops once or 5 mL per massage session. These are research doses, not recommendations.^{1,2,3,5,8,10,11}

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

Interactions

0 agents

None found in our sources.

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Sweet violet and your picks, and between your picks.

Add a supplement or medicine

Most cited:

Add a supplement or medicine you take to check it against Sweet violet.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Who should be careful

5 groups

People on sleep medicines or sedatives: Violet is studied for sleep, but no trial has tested it with sleeping pills, benzodiazepines or other sedatives, so any added effect is unknown.^1,7
People on other medicines: No published drug-interaction study or case report was found for sweet violet, and the cited trials describe none, so effects with blood thinners, diabetes drugs or other medicines are unknown. NCCIH notes that supplements can interact with medicines.^1,2,6,9
People with asthma: The asthma trial used violet syrup only alongside a short-acting beta-agonist; it was not tested as a replacement for asthma medicine.⁴
Children: Children were studied only in an add-on cough trial and a topical fever trial in hospital.^4,5
Pregnancy and breastfeeding: NCCIH notes that many dietary supplements have not been tested in pregnant women or nursing mothers, and no sweet violet trial enrolled them.⁹

How to read the label

What to check on the Supplement Facts panel.

How to read the label

3 checks

Syrup, nasal oil or skin oil

Most sleep evidence comes from oral syrup and from violet oil used as nasal drops; the fever study rubbed oil on the skin. Products sold as capsules were not the forms tested.^1,3,5

Volume, not milligrams

Trials dosed by millilitres of syrup or drops of oil, and the abstracts give no standardized extract content, so a mg figure on a label cannot be matched to a studied dose.^1,2,3

The base oil

Nasal violet oil in the trials was violet extract in almond or sesame oil. In the dry eye trial, violet-almond oil did better than plain almond oil.^3,8,10

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

6 answers

Does sweet violet help sleep?

Small Iranian trials and a 5-trial meta-analysis found better sleep-quality scores than placebo, using syrup or nasal oil for about a month. Sleep latency and efficiency did not improve significantly in the pooled analysis.^1,2,7

Does violet syrup help a cough?

Added to usual care, it shortened time to cough relief in children with intermittent asthma and eased cough in adult COVID-19 outpatients.^4,6

Does sweet violet interact with medicines?

Unknown. No drug-interaction study or case report was found, and the trials do not describe testing it with sleep medicines, blood thinners or other drugs. NCCIH notes that supplements can interact with medicines.^1,7,9

Is sweet violet the same as African violet?

No. Sweet violet is Viola odorata; African violets are unrelated houseplants (Saintpaulia).

How is violet oil used for sleep?

In the trials, a few drops of violet extract in almond or sesame oil were placed in each nostril nightly. Placebo drops also improved sleep, though less.^3,8

How strong is the evidence?

Low to moderate: trials are small, short, mostly from Iran, and mix different forms and doses.⁷

Sources

11 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

11 sources

1Effects of Viola odorata syrup on sleep quality in menopausal women: a randomized, triple-blind, controlled trial.RCT Sleep Breath, 2024 · PMID 38177831
2Effects of Viola odorata as an Add-On Therapy on Insomnia in Patients with Obsession or Depression: A Pilot Randomized Double-Blind Placebo-Controlled Trial.Pilot RCT J Altern Complement Med, 2020 · PMID 32073874
3Efficacy of Violet oil, a traditional Iranian formula, in patients with chronic insomnia: A randomized, double-blind, placebo-controlled study.RCT J Ethnopharmacol, 2018 · PMID 29217495
4The Effect of Viola odorata Flower Syrup on the Cough of Children With Asthma: A Double-Blind, Randomized Controlled Trial.RCT J Evid Based Complementary Altern Med, 2015 · PMID 25954025
5The Effect of Viola Odorata L. Oil for Fever in Children: A Randomized Triple-blinded Placebo-controlled Clinical Trial.RCT Curr Drug Discov Technol, 2020 · PMID 31250761
6Efficacy and safety of add-on Viola odorata L. in the treatment of COVID-19: A randomized double-blind controlled trial.RCT J Ethnopharmacol, 2023 · PMID 36535329
7The Efficacy of V. odorata Extract in the Treatment of Insomnia: A Systematic Review and Meta-Analysis.Meta-analysis Front Neurol, 2022 · PMID 35734476
8Efficacy of Viola odorata in Treatment of Chronic Insomnia.Open-label trial Iran Red Crescent Med J, 2014 · PMID 25763239
9Using Dietary Supplements WiselyFact sheet National Center for Complementary and Integrative Health (NCCIH), 2019 · nccih.nih.gov
10Effects of intranasal administration of violet oil in dry eye disease.RCT Clin Exp Optom, 2019 · PMID 31060104
11The effect of massage and topical violet oil on the severity of pruritus and dry skin in hemodialysis patients: A randomized controlled trial.RCT Complement Ther Med, 2019 · PMID 31331569

What changed

Every dated change to this page: what changed, who made it and why.

Change log

3 entries

Dated changes to this page
Date	Change	Who and why
Oct 21, 2026evidence, summary, forms, studied doses, who should be careful, label guide, insights, FAQ, related links, sources	Added two graded rows: a 2019 dry eye trial of nasal violet oil (PMID 31060104) and a 2019 trial of violet oil massage for itch in hemodialysis (PMID 31331569). New skin-oil form, two label-guide steps, two insights, an interactions FAQ and a sleep hub link. PubMed searched for Viola odorata trials and meta-analyses through 2026: the 2024 menopause trial remains the newest; a 2020 allergic rhinitis trial (PMID 32507426) has no abstract and was not added. Interactions: no study or case report found; the table stays empty and the medicines note says so. Fact-checked against the sources; corrected: the itch trial note no longer calls it unblinded, since the abstract does not report blinding.	Writer: Kymata Health EditorialTrigger: A–Z page audit
Oct 14, 2026who should avoid	Pregnancy and breastfeeding caution re-sourced to NCCIH (agency source) instead of trial reports	Writer: Kymata Health EditorialTrigger: adversarial review
Oct 14, 2026all	Initial editorial evidence review	Writer: Kymata Health EditorialTrigger: new page

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