Peptides / Brain and mood

Natural peptide · 3 amino acids · 284.4 Da

MIF-1 (Pro-Leu-Gly-NH2)

MIF-1, also called melanostatin, is a natural three-amino-acid peptide, different from the immune protein MIF, and no approval as a drug was found. Most studies are in animals, with small studies in people on mood. PepBank shows 18 results on MIF-1 from 5 studies in people, and 299 from animal and lab studies. The strongest evidence is a randomized trial in people. Data as of 2026-10-30.

Also known as MIF-1, MIF-I, Melanostatin I, Melanostatin MIF-I, Pro-Leu-Gly-NH2, Prolyl-leucyl-glycinamide

3 amino acids, from first to lastPLG

Evidence level: Mostly animal studies299 of 317 results come from studies in animals and lab cells. 5 studies in people.

Results in people

6% of 317 results

Results in animals

253

80% of 317 results

Results in lab cells

15% of 317 results

From computer models

0% of 317 results

Overview

MIF-1 (Pro-Leu-Gly-NH2) at a glance

What it is	Natural peptide, 3 amino acids
Approval	Regulatory status not recorded
In sport	Status unknown
Studies	89 studies with results. 87 of them gave MIF-1, with 317 results. 18 in people253 in animals46 in lab cells
Best study in people	Randomized controlled trial with 20 people (1988)
Clinical trials	None registered
Community use	Anhedonia and treatment-resistant depression interest

The science

What is MIF-1?

A naturally derived tripeptide also called melanostatin I, distinct from the macrophage MIF protein.

Amino acids in one chain

MIF-1 (Pro-Leu-Gly-NH2) 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

P1LG

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

Structure

MIF-1 (Pro-Leu-Gly-NH2) is a natural peptide of 3 amino acids, with no ring, 1 changed amino acid.

Formula

C₁₃H₂₄N₄O₃

Molecular weight

284.4 g/mol

CAS number

2002-44-0

Target

Dopamine D2 receptor: Positive allosteric modulationEvidence: Preclinical studies report increased dopamine agonist responses. PMID 10821635 reports PLG effects in rat striatal membranes. This does not establish clinical efficacy.

Development

Highest phase: unknown.

Identifiers

PubChem 92910, UNII 3KY24B4Q62, UniProt P01178

Full sequence, SMILES and InChIKey

InChIKey
NOOJLZTTWSNHOX-UWVGGRQHSA-N

SMILES
CC(C)C[C@@H](C(=O)NCC(=O)N)NC(=O)[C@@H]1CCCN1

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

The evidence

What MIF-1 studies show

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

Mostly animal studies299 of 317 results come from studies in animals and lab cells. 5 studies in people.

Mood, stress and behavior

39 results · 14 in people · 25 animal

In patients with major depression, MIF‑1 improved depression ratings more than placebo after the first week. Journal of affective disorders, 1994

Top results

In patients with major depression, MIF‑1 improved depression ratings more than placebo after the first week. (Journal of affective disorders, 1994)
In rats with chronic stress, MIF‑1 increased open-field activity. (Pharmacology, biochemistry, and behavior, 1989)
In rats tolerant to heroin, MIF‑1 did not reduce the amount of heroin they self-injected. (Life sciences, 1985)

Pain

30 results · 2 in people · 28 animal

In men given morphine, MIF‑1 increased pain during cold-water immersion versus placebo at 45 and 75 minutes. Pharmacology, biochemistry, and behavior, 1984

Top results

In men given morphine, MIF‑1 increased pain during cold-water immersion versus placebo at 45 and 75 minutes. (Pharmacology, biochemistry, and behavior, 1984)
In rats, daily MIF prevented tolerance to beta-endorphin pain relief. (The Journal of pharmacology and experimental therapeutics, 1981)
In men given morphine, MIF‑1 increased pain after foot removal versus placebo at all four assessment times. (Pharmacology, biochemistry, and behavior, 1984)

Daily life and fitness

10 results · 2 in people · 8 animal

In healthy men, PLG increased writing time compared with placebo. Pharmacopsychiatry, 1988

Top results

In healthy men, PLG increased writing time compared with placebo. (Pharmacopsychiatry, 1988)
In healthy men, PLG reduced writing pressure compared with placebo. (Pharmacopsychiatry, 1988)
In rats given repeated saline injections, multiple MIF injections did not change beta-endorphin-induced catalepsy. (The Journal of pharmacology and experimental therapeutics, 1981)

Heart and blood vessels

21 results · 21 animal

In rats, PLG reduced the blood pressure rise after brain stimulation. Brain research, 1984

Top results

In rats, PLG reduced the blood pressure rise after brain stimulation. (Brain research, 1984)
In rats, PLG did not change the heart response to brain stimulation. (Brain research, 1984)
In rats under anesthesia, PLG reduced the blood pressure response to electrical stimulation. (European journal of pharmacology, 1983)

Weight and appetite

8 results · 8 animal

In rats, PLG alone decreased food intake. Pharmacology, biochemistry, and behavior, 1984

Top results

In rats, PLG alone decreased food intake. (Pharmacology, biochemistry, and behavior, 1984)
In rats, daily PLG increased the rise in accepted ethanol concentrations. (Pharmacology, biochemistry, and behavior, 1979)
In mice, PLG increased weight loss after naloxone-induced morphine withdrawal. (European journal of pharmacology, 1981)

Memory and thinking

7 results · 7 animal

In rats, PLG at 0.6 micrograms/kg weakened social recognition, as oxytocin did at the same dose. European journal of pharmacology, 1996

Top results

In rats, PLG at 0.6 micrograms/kg weakened social recognition, as oxytocin did at the same dose. (European journal of pharmacology, 1996)
In rats, PLG reduced memory loss after electroconvulsive shock in a dose-dependent manner. (Pharmacology, biochemistry, and behavior, 1988)
In rats, PLG did not affect extinction of a learned food response. (Acta physiologica Hungarica, 1988)

All 5 studies in people

In people

In healthy men, PLG increased writing time compared with placebo.

1988Pharmacopsychiatry20 people

In people

In patients with major depression, MIF‑1 improved depression ratings more than placebo after the first week.

1994Journal of affective disorders20 people

In people

In patients with depression, substantial improvement occurred in 5 of 8 receiving low-dose MIF-I versus 1 of 10 receiving high-dose MIF-I.

1978The American journal of psychiatry18 people

In people

In patients with depression, substantial improvement occurred more often with MIF‑1 at 75 mg per day than at 750 mg per day.

1976Pharmacology, biochemistry, and behavior18 people

In people

In men given morphine, MIF‑1 increased pain during cold-water immersion versus placebo at 45 and 75 minutes.

1984Pharmacology, biochemistry, and behavior8 people

All 89 MIF-1 studies by area Open the Scientific page

Key MIF-1 studies

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

People
Effects of the neuropeptide PLG (L-prolyl-leucyl-glycinamide) on writing pressure and speed in healthy subjects
Steinwachs et al. 1988 · Pharmacopsychiatry · 20 people · cited by 1
2 results
People
Improvement in major depression after low subcutaneous doses of MIF-1
Ehrensing et al. 1994 · Journal of affective disorders · 20 people · cited by 29
3 results
People
Dose-related biphasic effect of prolyl-leucyl-glycinamide (MIF-I) in depression
Ehrensing et al. 1978 · The American journal of psychiatry · 18 people · cited by 66
5 results
People
Clinical investigations for emotional effects of neuropeptide hormones
Ehrensing et al. 1976 · Pharmacology, biochemistry, and behavior · 18 people · cited by 13
6 results
People
Antagonism of morphine analgesia by prolyl-leucyl-glycinamide (MIF-1) in humans
Ehrensing et al. 1984 · Pharmacology, biochemistry, and behavior · 8 people · cited by 29
2 results

All 89 MIF-1 (Pro-Leu-Gly-NH2) studies

MIF-1 clinical trials

ClinicalTrials.gov lists no trial of MIF-1. A trial under another name may exist.

Status and safety

Is MIF-1 approved?

FDA

United States

Status unknown

Status unknown.

EMA

European Union

Status unknown

Status unknown.

WADA

Sport

Not recorded

Status unknown.

Regulatory status not recorded. Status unknown.

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

MIF-1 side effects and safety

PepBank has 10 safety results from studies of MIF-1. None of them come from studies in people, so they do not show what happens in people.

Safety results from studies (10)

In rats with chronic stress, high-dose MIF‑1 increased pain sensitivity. (Pharmacology, biochemistry, and behavior, 1989)
In mice dependent on levorphanol, intermediate-dose PLG triggered withdrawal. (Life sciences, 1984)
In mice dependent on morphine, intermediate-dose PLG triggered withdrawal. (European journal of pharmacology, 1984)
In mice, PLG increased the fall in body temperature after naloxone-induced morphine withdrawal. (European journal of pharmacology, 1981)
In mice dependent on levorphanol, high-dose PLG triggered withdrawal. (Life sciences, 1984)
In mice dependent on morphine, high-dose PLG triggered withdrawal. (European journal of pharmacology, 1984)
In mice, PLG increased weight loss after naloxone-induced morphine withdrawal. (European journal of pharmacology, 1981)
In morphine-dependent mice, PLG before naloxone did not change the withdrawal-related fall in body temperature. (European journal of pharmacology, 1981)
In morphine-dependent mice, PLG before naloxone did not change withdrawal-related weight loss. (European journal of pharmacology, 1981)
In cells, MIF‑1 caused mild toxicity at the tested concentration. (ACS medicinal chemistry letters, 2023)

See every safety result on the Scientific page

Doses studied (40 shown)

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

Dose as reported	Class	Species	Route	Duration	Design	Source
25 mg	Human	human	intravenous	Not reported	Randomized trial in people · n = 20	Steinwachs 1988
10 mg daily	Human	human	subcutaneous	5 consecutive days	Trial in people without random groups · n = 20	Ehrensing 1994
75 mg/day	Human	human	Not reported	Not reported	Trial in people without random groups · n = 18	Ehrensing 1978
75 mg per day	Human	human	Not reported	Not reported	Trial in people without random groups · n = 18	Ehrensing 1976
750 mg/day	Human	human	Not reported	Not reported	Trial in people without random groups · n = 15	Ehrensing 1978
750 mg per day	Human	human	Not reported	Not reported	Trial in people without random groups · n = 15	Ehrensing 1976
60 mg	Human	human	oral	Not reported	Trial in people without random groups · n = 8	Ehrensing 1984
60 mg per day	Human	human	Not reported	6 days	Trial in people without random groups	Ehrensing 1976
150 mg per day	Human	human	Not reported	6 days	Trial in people without random groups	Ehrensing 1976
0.001, 0.01, 0.1, 1.0 and 10.0 mg/kg	Animal	Carassius auratus	intracranial	Not reported	Study in live animals	Ehrensing 1982
10 mg kg-1	Animal	Not reported	subcutaneous	Not reported	Study in live animals	Chiu 1979
2 mg/kg per day	Animal	rat	subcutaneous	Not reported	Study in live animals	Bhargava 1984
0.6 micrograms/kg	Animal	rat	subcutaneous	Not reported	Study in live animals	Popik 1996
6 micrograms/kg	Animal	rat	subcutaneous	Not reported	Study in live animals	Popik 1996
0.6 ng/kg	Animal	rat	subcutaneous	Not reported	Study in live animals	Popik 1996
6 ng/kg	Animal	rat	subcutaneous	Not reported	Study in live animals	Popik 1996
10 nmol	Animal	mouse	intraventricular	Not reported	Study in live animals	Durham 1991
0.1 mg/kg	Animal	rat	intraperitoneal	20 days	Study in live animals	Pignatiello 1989
1.0 mg/kg	Animal	rat	intraperitoneal	20 days	Study in live animals	Pignatiello 1989
10.0 mg/kg	Animal	rat	intraperitoneal	20 days	Study in live animals	Pignatiello 1989
2 mg/kg	Animal	rat	subcutaneous	Not reported	Study in live animals	Bhargava 1981
50 microgram daily	Animal	mouse	injection	Not reported	Study in live animals	Walter 1979
0.5 microgram per mouse	Animal	mouse	injection	Not reported	Study in live animals	Walter 1979
10 microgram daily	Animal	rat	subcutaneous	Not reported	Study in live animals	Mucha 1979
1 microgram	Animal	rat	subcutaneous	Not reported	Study in live animals	Mucha 1979
0.2, 0.5, 1.0 and 5.0 mg/kg	Animal	Rat	SC	Not reported	Study in live animals	Hara 1986
1.0 mg/kg	Animal	Rat	SC	Not reported	Study in live animals	Hara 1986
0.01 mg/kg	Animal	rat	intraperitoneal	Not reported	Study in live animals	Pulvirenti 1988
10 ng/mouse	Animal	mouse	intracerebroventricular	Not reported	Study in live animals	Contreras 1984
10 micrograms/mouse	Animal	mouse	intracerebroventricular	Not reported	Study in live animals	Contreras 1984
100 micrograms/mouse	Animal	mouse	intracerebroventricular	Not reported	Study in live animals	Contreras 1984
0.01 mg/kg	Animal	rat	intraperitoneal	Not reported	Study in live animals	Kostowski 1991
6 mg/kg	Animal	rat	Not reported	Not reported	Study in live animals	Koyuncuoğlu 1984
1.0 mg/kg/day	Animal	rat	intraperitoneal	32 days from birth	Study in live animals	Saleh 1989
10 ng/mouse	Animal	mouse	intracerebroventricular	Not reported	Study in live animals	Contreras 1984
10 micrograms/mouse	Animal	mouse	intracerebroventricular	Not reported	Study in live animals	Contreras 1984
100 micrograms/mouse	Animal	mouse	intracerebroventricular	Not reported	Study in live animals	Contreras 1984
2.0 mg/kg per day	Animal	rat	subcutaneous	7 or 8 days	Study in live animals	Kostrzewa 1989
10 mumol/kg per day	Animal	Rat	Subcutaneous	Not reported	Study in live animals	Bhargava 1986
0.01-10 mg/kg	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Kavaliers 1985

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 source reports interest in this product. Its statements do not establish clinical benefit or a safe regimen.

Reported routines and cautions

What people use it for

Anhedonia and treatment-resistant depression interestS1

Reported regimens

Regimens that community sources report for MIF-1. Community-reported, not tested in trials.
Context	Route	Amount	How often	How long	Agreement	Sources
Reported anhedonia and depression self-experimentation	subcutaneous injection	10 mg per dose	once daily	5 to 7 days	Single guide source. The site reports no product sales, commissions or referral fees.	S1

Cautions

The source relies on limited old clinical research. It does not establish a safe or effective community regimen.S1

Community sources

S1MIF-1 source guide (opens in a new tab)peptideschedule.com

Gaps

Underlying user reports were not independently checked. Source statements do not establish safety, efficacy, or an approved dose.

Questions and more

Ask a question about MIF-1

The answer links to every study it uses.

What does the evidence say about MIF-1?Is MIF-1 tested in people?Compare with Selank Compare with Delta sleep-inducing peptide (DSIP)

Sources

Database: PepBank data for MIF-1 (data version 308560)
Regulator: WADA status record
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 MIF-1

Curo is a peptide shop. PepBank and Curo have the same owner. See the Curo catalog (opens in a new tab).

MIF-1 (Pro-Leu-Gly-NH2)

Also known as MIF-1, MIF-I, Melanostatin I, Melanostatin MIF-I, Pro-Leu-Gly-NH2, Prolyl-leucyl-glycinamide

What it is

Natural peptide, 3 amino acids

Approval

Regulatory status not recorded

In sport

Status unknown

Studies

89 studies with results. 87 of them gave MIF-1, with 317 results.
18 in people253 in animals46 in lab cells

Best study in people

Randomized controlled trial with 20 people (1988)

Clinical trials

None registered

Community use

Anhedonia and treatment-resistant depression interest

Dose as reported

Class

Species

Route

Duration

Design

Source

25 mg

Human

human

intravenous

Not reported

Randomized trial in people · n = 20

Steinwachs 1988

10 mg daily

Human

human

subcutaneous

5 consecutive days

Trial in people without random groups · n = 20

Ehrensing 1994

75 mg/day

Human

human

Not reported

Trial in people without random groups · n = 18

Ehrensing 1978

75 mg per day

Human

human

Not reported

Trial in people without random groups · n = 18

Ehrensing 1976

750 mg/day

Human

human

Not reported

Trial in people without random groups · n = 15

Ehrensing 1978

750 mg per day

Human

human

Not reported

Trial in people without random groups · n = 15

Ehrensing 1976

60 mg

Human

human

oral

Not reported

Trial in people without random groups · n = 8

Ehrensing 1984

60 mg per day

Human

human

Not reported

6 days

Trial in people without random groups

Ehrensing 1976

150 mg per day

Human

human

Not reported

6 days

Trial in people without random groups

Ehrensing 1976

0.001, 0.01, 0.1, 1.0 and 10.0 mg/kg

Animal

Carassius auratus

intracranial

Not reported

Study in live animals

Ehrensing 1982

10 mg kg-1

Animal

Not reported

subcutaneous

Not reported

Study in live animals

Chiu 1979

2 mg/kg per day

Animal

rat

subcutaneous

Not reported

Study in live animals

Bhargava 1984

0.6 micrograms/kg

Animal

rat

subcutaneous

Not reported

Study in live animals

Popik 1996

6 micrograms/kg

Animal

rat

subcutaneous

Not reported

Study in live animals

Popik 1996

0.6 ng/kg

Animal

rat

subcutaneous

Not reported

Study in live animals

Popik 1996

6 ng/kg

Animal

rat

subcutaneous

Not reported

Study in live animals

Popik 1996

10 nmol

Animal

mouse

intraventricular

Not reported

Study in live animals

Durham 1991

0.1 mg/kg

Animal

rat

intraperitoneal

20 days

Study in live animals

Pignatiello 1989

1.0 mg/kg

Animal

rat

intraperitoneal

20 days

Study in live animals

Pignatiello 1989

10.0 mg/kg

Animal

rat

intraperitoneal

20 days

Study in live animals

Pignatiello 1989

2 mg/kg

Animal

rat

subcutaneous

Not reported

Study in live animals

Bhargava 1981

50 microgram daily

Animal

mouse

injection

Not reported

Study in live animals

Walter 1979

0.5 microgram per mouse

Animal

mouse

injection

Not reported

Study in live animals

Walter 1979

10 microgram daily

Animal

rat

subcutaneous

Not reported

Study in live animals

Mucha 1979

1 microgram

Animal

rat

subcutaneous

Not reported

Study in live animals

Mucha 1979

0.2, 0.5, 1.0 and 5.0 mg/kg

Animal

Rat

Not reported

Study in live animals

Hara 1986

1.0 mg/kg

Animal

Rat

Not reported

Study in live animals

Hara 1986

0.01 mg/kg

Animal

rat

intraperitoneal

Not reported

Study in live animals

Pulvirenti 1988

10 ng/mouse

Animal

mouse

intracerebroventricular

Not reported

Study in live animals

Contreras 1984

10 micrograms/mouse

Animal

mouse

intracerebroventricular

Not reported

Study in live animals

Contreras 1984

100 micrograms/mouse

Animal

mouse

intracerebroventricular

Not reported

Study in live animals

Contreras 1984

0.01 mg/kg

Animal

rat

intraperitoneal

Not reported

Study in live animals

Kostowski 1991

6 mg/kg

Animal

rat

Not reported

Study in live animals

Koyuncuoğlu 1984

1.0 mg/kg/day

Animal

rat

intraperitoneal

32 days from birth

Study in live animals

Saleh 1989

10 ng/mouse

Animal

mouse

intracerebroventricular

Not reported

Study in live animals

Contreras 1984

10 micrograms/mouse

Animal

mouse

intracerebroventricular

Not reported

Study in live animals

Contreras 1984

100 micrograms/mouse

Animal

mouse

intracerebroventricular

Not reported

Study in live animals

Contreras 1984

2.0 mg/kg per day

Animal

rat

subcutaneous

7 or 8 days

Study in live animals

Kostrzewa 1989

10 mumol/kg per day

Animal

Rat

Subcutaneous

Not reported

Study in live animals

Bhargava 1986

0.01-10 mg/kg

Animal

mouse

intraperitoneal

Not reported

Study in live animals

Kavaliers 1985

Context

Route

Amount

How often

How long

Agreement

Sources

Reported anhedonia and depression self-experimentation

subcutaneous injection

10 mg per dose

once daily

5 to 7 days

Single guide source. The site reports no product sales, commissions or referral fees.

MIF-1 (Pro-Leu-Gly-NH2)

MIF-1 (Pro-Leu-Gly-NH2) at a glance

What is MIF-1?

MIF-1 (Pro-Leu-Gly-NH2) structure and chemistry

What MIF-1 studies show

Mood, stress and behavior

Pain

Daily life and fitness

Heart and blood vessels

Weight and appetite

Memory and thinking

All 5 studies in people

Key MIF-1 studies

MIF-1 clinical trials

Is MIF-1 approved?

MIF-1 side effects and safety

How people use it

What people use it for

Reported regimens

Cautions

Community sources

Ask a question about MIF-1

Related peptides

Sources

MIF-1 (Pro-Leu-Gly-NH2)

MIF-1 (Pro-Leu-Gly-NH2) at a glance

What is MIF-1?

MIF-1 (Pro-Leu-Gly-NH2) structure and chemistry

What MIF-1 studies show

Mood, stress and behavior

Pain

Daily life and fitness

Heart and blood vessels

Weight and appetite

Memory and thinking

All 5 studies in people

Key MIF-1 studies

MIF-1 clinical trials

Is MIF-1 approved?

MIF-1 side effects and safety

How people use it

What people use it for

Reported regimens

Cautions

Community sources

Ask a question about MIF-1

Related peptides

Sources