Peptides / Brain and mood

Synthetic analog · 3 amino acids · 315.3 Da

Trofinetide

ApprovedNot banned in sport

Trofinetide (Daybue) is an analog of Gly-Pro-Glu, a three-amino-acid piece of IGF-1, approved in the US and EU for Rett syndrome. Studies in people tested it on Rett syndrome symptoms, communication and how the body handles it, and tracked side effects and dropouts. PepBank shows 168 results on trofinetide from 24 studies in people, and 35 from animal and lab studies. The strongest evidence is a randomized trial in people. Data as of 2026-10-30.

Also known as Daybue, NNZ-2566

3 amino acids, from first to lastGXE

Evidence level: Large trials in people168 of 204 results come from studies in people, including randomized trials.

Results in people

168

82% of 204 results

Results in animals

16% of 204 results

Results in lab cells

under 1% of 204 results

From computer models

under 1% of 204 results

Overview

Trofinetide at a glance

What it is	Synthetic analog, 3 amino acids
Approval	Approved in the US and EU (Daybue, 2023)
In sport	Not listed as banned by WADA
Studies	31 studies with results. All of them gave trofinetide, with 204 results. 168 in people33 in animals2 in lab cells1 from computer models
Best study in people	Randomized controlled trial with 187 people (2023)
Clinical trials	13 registered: 1 active or planned, 4 with posted results
Community use	Rett syndrome in adults and pediatric patients 2 years of age and older

The science

What is trofinetide?

Trofinetide is an analog of the IGF-1 N-terminal tripeptide Gly-Pro-Glu.

Amino acids in one chain

The history of trofinetide

2009
The oldest paper on trofinetide in PepBank is from 2009.
2010April
A registered trial of trofinetide started (NCT00805818).
2023March
FDA approved Daybue for rett syndrome in adults and pediatric patients 2 years of age and older.

Trofinetide structure and chemistry

The key facts about the molecule. Long codes are in the closed section below.

Sequence, 3 amino acidsFrom the first amino acid to the last

G1X−E

Darker means more water-repelling+ and − show charge in the bodyOutlined: changed amino acid

Structure

Trofinetide is a synthetic analog of 3 amino acids, with no ring, 1 changed amino acid.

Formula

C₁₃H₂₁N₃O₆

Molecular weight

315.3 g/mol

CAS number

853400-76-7

Development

Highest phase: past the trial stage (see status).

Identifiers

PubChem 11318905, ChEMBL CHEMBL197084, UNII Z2ME8F52QL, DrugBank DB06045

Full sequence, SMILES and InChIKey

InChIKey
BUSXWGRAOZQTEY-SDBXPKJASA-N

SMILES
C[C@]1(CCCN1C(=O)CN)C(=O)N[C@@H](CCC(=O)O)C(=O)O

See charge, composition and 3D structure on the Scientific page

The evidence

What trofinetide studies show

Results grouped by what the studies measured. Each card shows where its results come from.

Large trials in people168 of 204 results come from studies in people, including randomized trials.

Autism and child development

28 results · 26 in people · 1 animal

In females with Rett syndrome, trofinetide reduced symptom scores more than placebo at week 12. Nature medicine, 2023

Top results

In females with Rett syndrome, trofinetide reduced symptom scores more than placebo at week 12. (Nature medicine, 2023)
In females with Rett syndrome, social communication scores declined less with trofinetide than placebo at week 12. (Nature medicine, 2023)
In males with fragile X syndrome, trofinetide at 70 mg/kg met prespecified benefit criteria versus placebo. (Pediatric neurology, 2020)

Daily life and fitness

8 results · 6 in people · 2 animal

Caregivers reported improved hand use in 42.3% of LILAC/LILAC-2 trofinetide participants. Clinical therapeutics, 2025

Top results

Caregivers reported improved hand use in 42.3% of LILAC/LILAC-2 trofinetide participants. (Clinical therapeutics, 2025)
All interviewed caregivers of young girls with RTT were satisfied or very satisfied with trofinetide benefits. (Med, 2025)
Among caregivers of females with Rett syndrome receiving trofinetide, 96% were satisfied or very satisfied with its benefits. (Med, 2024)

Brain and nerves

16 results · 4 in people · 10 animal · 2 lab

In Rett syndrome care, 71%-90% of caregivers reported behavioral improvement during trofinetide treatment across months 1 to 12. Developmental medicine and child neurology, 2026

Top results

In Rett syndrome care, 71%-90% of caregivers reported behavioral improvement during trofinetide treatment across months 1 to 12. (Developmental medicine and child neurology, 2026)
In rats with focal stroke, intravenous NNZ-2566 reduced infarct area. (Journal of the neurological sciences, 2009)
In rats with stroke, NNZ-2566 before seizures reduced seizure incidence versus saline. (Journal of cerebral blood flow and metabolism, 2009)

Memory and thinking

1 result · 1 in people

Caregivers reported improved attention, focus, or concentration in 26.9% of LILAC/LILAC-2 trofinetide participants. Clinical therapeutics, 2025

Top results

Caregivers reported improved attention, focus, or concentration in 26.9% of LILAC/LILAC-2 trofinetide participants. (Clinical therapeutics, 2025)

Mood, stress and behavior

1 result · 1 in people

Caregivers reported improved engagement with others in 42.3% of LILAC/LILAC-2 trofinetide participants. Clinical therapeutics, 2025

Top results

Caregivers reported improved engagement with others in 42.3% of LILAC/LILAC-2 trofinetide participants. (Clinical therapeutics, 2025)

Sleep

1 result · 1 in people

In pediatric RTT trofinetide safety reports, hypersomnia was reported more often in younger children. Clinical therapeutics, 2025

Top results

In pediatric RTT trofinetide safety reports, hypersomnia was reported more often in younger children. (Clinical therapeutics, 2025)

All 31 trofinetide studies by area Open the Scientific page

Key trofinetide studies

Studies in people come first, then studies in animals and in the lab.

People
Trofinetide for the treatment of Rett syndrome: a randomized phase 3 study
Neul et al. 2023 · Nature medicine · 187 people · cited by 154
4 results
People
Trofinetide Treatment Demonstrates a Benefit Over Placebo for the Ability to Communicate in Rett Syndrome
Neul et al. 2024 · Pediatric neurology · cited by 22
3 results
People
A Phase 1, Open-Label Study to Evaluate the Effects of Food and Evening Dosing on the Pharmacokinetics of Oral Trofinetide in Healthy Adult Subjects
Darwish et al. 2022 · Clinical drug investigation · 41 people · cited by 13
8 results
People
A Phase 1, Randomized, Open-Label Study to Assess the Bioequivalence of Trofinetide as a Ready-to-Use Oral Solution and Constituted Powder for Oral Solution in Healthy Adults
Darwish et al. 2026 · Advances in therapy · 38 people · cited by 0
12 results
People
Double-blind, randomized, placebo-controlled study of trofinetide in pediatric Rett syndrome
Glaze et al. 2019 · Neurology · cited by 113
5 results

All 31 Trofinetide studies

Trofinetide clinical trials

ClinicalTrials.gov lists 13 trials of trofinetide. 1 is active or planned, and 4 have posted results. PepBank does not show trial results.

Solid bars are dates that happened. Hatched bars are planned dates. Data from ClinicalTrials.gov.

Study of Trofinetide for the Treatment of Girls and Women With Rett Syndrome (LAVENDER™)

Phase 3completed187 people

Open-Label Extension Study of Trofinetide for the Treatment of Girls and Women With Rett Syndrome

Phase 3completed154 people

Open-Label Extension Study of Trofinetide for Rett Syndrome

Phase 3terminated77 planned

All 7 Trofinetide trials

Status and safety

Is trofinetide approved?

FDA

United States

Approved

An approved medicine contains it.

EMA

European Union

Approved

An approved medicine contains it.

WADA

Sport

Not banned

Not on the 2026 Prohibited List.

Yes. Approved in the US and EU (Daybue, 2023). The FDA label for Daybue says: “Rett syndrome in adults and pediatric patients 2 years of age and older” Not listed as banned by WADA.

Laws and labels change, so check the regulator for the current status.

Trofinetide side effects and safety

PepBank has 62 safety results from studies of trofinetide. 61 of them come from studies in people.

Safety results from studies (62)

In females with Rett syndrome, diarrhea occurred in 80.6% with trofinetide versus 19.1% with placebo, mostly with mild-to-moderate severity. (Nature medicine, 2023)
In females with Rett syndrome receiving trofinetide, 74.7% had diarrhea. (Med, 2024)
In females with Rett syndrome receiving trofinetide, 53.2% had diarrhea in LILAC-2. (Med, 2024)
In healthy adults, oral trofinetide was well tolerated. (Clinical drug investigation, 2022)
In healthy adults receiving trofinetide formulations, diarrhea was the most frequent adverse event, affecting 6 participants (15.8%). (Advances in therapy, 2026)
In young girls with RTT receiving trofinetide, 80.0% had mild or moderate diarrhea. (Med, 2025)
After single-dose trofinetide, 20.0% of participants with moderate renal impairment reported adverse events. (European journal of drug metabolism and pharmacokinetics, 2025)
In children and adolescents with Rett syndrome, trofinetide at 50 mg/kg twice daily was well tolerated and generally safe. (Neurology, 2019)
In females with Rett syndrome, trofinetide at 35 mg/kg was well tolerated and generally safe. (Pediatric neurology, 2017)
In males with fragile X syndrome, trofinetide at 35 mg/kg twice daily was well tolerated and appeared generally safe. (Pediatric neurology, 2020)
In healthy men after trofinetide, two participants had mild adverse events that investigators considered unrelated to treatment. (Clinical drug investigation, 2024)
In FAERS, trofinetide was the primary suspected drug in 15,266 adverse event reports from 2,824 patients. (Frontiers in pharmacology, 2026)
Among individuals with RTT or MECP2-related disorders receiving trofinetide, 48.1% reported diarrhea. (Frontiers in neurology, 2026)
In Rett syndrome care, diarrhea incidence during trofinetide treatment was 23%-50% across weeks 1 to 12. (Developmental medicine and child neurology, 2026)
In adverse event reports, trofinetide was linked to gastric motility disorders. (PloS one, 2026)
Trofinetide was linked to disproportionate diarrhoea reporting compared with the reporting background in pediatric RTT safety data. (Clinical therapeutics, 2025)
In a girl with Rett syndrome, vomiting, pallor, and lethargy developed after 2 months of trofinetide treatment. (Journal of child neurology, 2026)
In females with Rett syndrome receiving trofinetide, 28.6% had vomiting. (Med, 2024)
In females with Rett syndrome receiving trofinetide, 11.0% had COVID-19. (Med, 2024)
In females with Rett syndrome receiving trofinetide, 21.4% stopped treatment because of diarrhea. (Med, 2024)
In females with Rett syndrome receiving trofinetide, 27.3% had COVID-19 in LILAC-2. (Med, 2024)
In females with Rett syndrome receiving trofinetide, 19.5% had vomiting in LILAC-2. (Med, 2024)
In healthy adults receiving trofinetide, vital signs did not change significantly. (Clinical drug investigation, 2022)
In healthy adults receiving trofinetide, laboratory test results did not change significantly. (Clinical drug investigation, 2022)

See every safety result on the Scientific page

Doses studied (22 shown)

The doses that these studies used. They are not recommendations.

Dose as reported	Class	Species	Route	Duration	Design	Source
12 g (60 mL oral solution)	Human	human	oral	Not reported	Randomized trial in people · n = 41	Darwish 2022
12,000 mg	Human	human	oral	single dose	Randomized trial in people · n = 38	Darwish 2026
200 mg/kg twice daily	Human	human	Not reported	42 days	Randomized trial in people	Glaze 2019
70 mg/kg twice daily	Human	human	Not reported	28 days	Randomized trial in people	Glaze 2017
70 mg/kg twice daily	Human	human	oral	28 days	Randomized trial in people	Berry-Kravis 2020
6 g in moderate renal impairment; 12 g in healthy participants	Human	human	oral	single dose	Trial in people without random groups · n = 20	Darwish 2025
6 g	Human	human	oral	single dose	Trial in people without random groups · n = 10	Darwish 2025
12 g	Human	human	oral	single dose	Trial in people without random groups · n = 10	Darwish 2025
50 mg/kg twice daily	Human	human	Not reported	42 days	Trial in people without random groups	Glaze 2019
100 mg/kg twice daily	Human	human	Not reported	42 days	Trial in people without random groups	Glaze 2019
35 mg/kg twice daily	Human	human	Not reported	14 or 28 days	Trial in people without random groups	Glaze 2017
35 mg/kg twice daily	Human	human	oral	28 days	Trial in people without random groups	Berry-Kravis 2020
12 g, mixture of trofinetide and radiolabeled trofinetide	Human	human	oral	single dose	Trial in people without random groups	Darwish 2024
6.0-100 mg/kg orally and 0.1-30 mg/kg intravenously	Human	human	oral and intravenous	Not reported	Observational study · n = 61	Oosterholt 2017
6.0-100 mg/kg	Human	human	oral	Not reported	Observational study	Oosterholt 2017
10 mg/kg bolus followed by 3 mg/kg/h infusion	Animal	rat	intravenous	Not reported	Study in live animals	Wei 2009
3-10 mg/kg/h	Animal	rat	intravenous infusion	4 h	Study in live animals	Bickerdike 2009
30-60 mg/kg	Animal	rat	oral	Not reported	Study in live animals	Bickerdike 2009
0.01-3 mg/kg/h	Animal	rat	intravenous	12 h	Study in live animals	Lu 2009
10- or 30-mg/kg bolus with infusion	Animal	rat	intravenous	12 h	Study in live animals	Lu 2009
3, 10, or 100 mg/kg bolus followed by 3 mg/kg per hour	Animal	rat	Not reported	12 h	Study in live animals	Lu 2009
10 or 100 mg/kg bolus followed by 3 mg/kg per hour	Animal	rat	Not reported	12 h	Study in live animals	Lu 2009

From the community

How people use it

What people report online. It comes from forums and guides, not from studies.

Community-reported. Not tested in trials.

The US label reports prescription use for Rett syndrome. This record selects one DAYBUE oral-solution regimen, not community practice.

Reported routines and cautions

What people use it for

Rett syndrome in adults and pediatric patients 2 years of age and olderS1

Reported regimens

Regimens that community sources report for Trofinetide. Community-reported, not tested in trials.
Context	Route	Amount	How often	How long	Agreement	Sources
Rett syndrome in patients aged 2 years and older who weigh at least 50 kg and have normal renal function or mild renal impairment. DAYBUE ready-to-use oral solution only.Official label dosing of an approved product	oralThe label also permits gastrostomy delivery. Gastrojejunal delivery must use the G-port.	12000 mg per dose	twice daily, in the morning and evening	Not stated	Single official US label source.	S1

Cautions

The label warns about diarrhea, dehydration, weight loss, vomiting, and aspiration or aspiration pneumonia after vomiting.S1

Status notes

Daybu received EU marketing authorisation on 20 August 2026 for neurobehavioural symptoms of Rett syndrome in patients aged 5 years and older.S2

Community sources

S1Daybue US prescribing information (opens in a new tab)dailymed.nlm.nih.gov
S2EMA regulatory information (opens in a new tab)ema.europa.eu

Gaps

This check did not establish a separate non-vendor community regimen. This record covers one selected US label regimen. Other weight bands, reduced renal doses, and powder preparation remain outside it. The label gives no fixed treatment duration.

Questions and more

Ask a question about trofinetide

The answer links to every study it uses.

What does the evidence say about trofinetide?Is trofinetide tested in people?Compare with Cerebrolysin Compare with Delta sleep-inducing peptide (DSIP)

Sources

Database: PepBank data for trofinetide (data version 308560)
Regulator: FDA status record
Regulator: EMA status record
Regulator: WADA status record
Trial registry: ClinicalTrials.gov
Community: community sources (forums and guides), as summarized in the PepBank community file

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

PepBank is a research reference. Talk to a doctor before you use any peptide.

Ask your AI about trofinetide

Trofinetide

ApprovedNot banned in sport

Also known as Daybue, NNZ-2566

What it is

Synthetic analog, 3 amino acids

Approval

Approved in the US and EU (Daybue, 2023)

In sport

Not listed as banned by WADA

Studies

31 studies with results. All of them gave trofinetide, with 204 results.
168 in people33 in animals2 in lab cells1 from computer models

Best study in people

Randomized controlled trial with 187 people (2023)

Clinical trials

13 registered: 1 active or planned, 4 with posted results

Community use

Rett syndrome in adults and pediatric patients 2 years of age and older

Dose as reported

Class

Species

Route

Duration

Design

Source

12 g (60 mL oral solution)

Human

human

oral

Not reported

Randomized trial in people · n = 41

Darwish 2022

12,000 mg

Human

human

oral

single dose

Randomized trial in people · n = 38

Darwish 2026

200 mg/kg twice daily

Human

human

Not reported

42 days

Randomized trial in people

Glaze 2019

70 mg/kg twice daily

Human

human

Not reported

28 days

Randomized trial in people

Glaze 2017

70 mg/kg twice daily

Human

human

oral

28 days

Randomized trial in people

Berry-Kravis 2020

6 g in moderate renal impairment; 12 g in healthy participants

Human

human

oral

single dose

Trial in people without random groups · n = 20

Darwish 2025

6 g

Human

human

oral

single dose

Trial in people without random groups · n = 10

Darwish 2025

12 g

Human

human

oral

single dose

Trial in people without random groups · n = 10

Darwish 2025

50 mg/kg twice daily

Human

human

Not reported

42 days

Trial in people without random groups

Glaze 2019

100 mg/kg twice daily

Human

human

Not reported

42 days

Trial in people without random groups

Glaze 2019

35 mg/kg twice daily

Human

human

Not reported

14 or 28 days

Trial in people without random groups

Glaze 2017

35 mg/kg twice daily

Human

human

oral

28 days

Trial in people without random groups

Berry-Kravis 2020

12 g, mixture of trofinetide and radiolabeled trofinetide

Human

human

oral

single dose

Trial in people without random groups

Darwish 2024

6.0-100 mg/kg orally and 0.1-30 mg/kg intravenously

Human

human

oral and intravenous

Not reported

Observational study · n = 61

Oosterholt 2017

6.0-100 mg/kg

Human

human

oral

Not reported

Observational study

Oosterholt 2017

10 mg/kg bolus followed by 3 mg/kg/h infusion

Animal

rat

intravenous

Not reported

Study in live animals

Wei 2009

3-10 mg/kg/h

Animal

rat

intravenous infusion

4 h

Study in live animals

Bickerdike 2009

30-60 mg/kg

Animal

rat

oral

Not reported

Study in live animals

Bickerdike 2009

0.01-3 mg/kg/h

Animal

rat

intravenous

12 h

Study in live animals

Lu 2009

10- or 30-mg/kg bolus with infusion

Animal

rat

intravenous

12 h

Study in live animals

Lu 2009

3, 10, or 100 mg/kg bolus followed by 3 mg/kg per hour

Animal

rat

Not reported

12 h

Study in live animals

Lu 2009

10 or 100 mg/kg bolus followed by 3 mg/kg per hour

Animal

rat

Not reported

12 h

Study in live animals

Lu 2009

Context

Route

Amount

How often

How long

Agreement

Sources

Rett syndrome in patients aged 2 years and older who weigh at least 50 kg and have normal renal function or mild renal impairment. DAYBUE ready-to-use oral solution only.Official label dosing of an approved product

oralThe label also permits gastrostomy delivery. Gastrojejunal delivery must use the G-port.

12000 mg per dose

twice daily, in the morning and evening

Not stated

Single official US label source.

Trofinetide

Trofinetide at a glance

What is trofinetide?

The history of trofinetide

Trofinetide structure and chemistry

What trofinetide studies show

Autism and child development

Daily life and fitness

Brain and nerves

Memory and thinking

Mood, stress and behavior

Sleep

Key trofinetide studies

Trofinetide clinical trials

Is trofinetide approved?

Trofinetide side effects and safety

How people use it

What people use it for

Reported regimens

Cautions

Status notes

Community sources

Ask a question about trofinetide

Related peptides

Sources

Trofinetide

Trofinetide at a glance

What is trofinetide?

The history of trofinetide

Trofinetide structure and chemistry

What trofinetide studies show

Autism and child development

Daily life and fitness

Brain and nerves

Memory and thinking

Mood, stress and behavior

Sleep

Key trofinetide studies

Trofinetide clinical trials

Is trofinetide approved?

Trofinetide side effects and safety

How people use it

What people use it for

Reported regimens

Cautions

Status notes

Community sources

Ask a question about trofinetide

Related peptides

Sources