Can peptides cause anxiety, low mood or irritability?

Each answer says whether anxiety, low mood or irritability was reported, and how often where that’s known. “Not reported” means the label or trials didn’t list it, not that it can’t happen. Talk to a doctor or pharmacist about any symptom that worries you.

From a product label 12

What the prescribing information says, with rates against placebo where the label gives them.

CerebrolysinApproved drug

LabelUncommon: agitation and confusion; aggression, depression and apathy are also reported (EU label). Russia’s label says some of these occurred as often on placebo.

ExenatideApproved drug

LabelFeeling jittery: 9% vs 4% on placebo. Anxiety and low mood aren’t listed; FDA’s 2026 review of 91 GLP-1 drug trials found no rise in either.

GHRP-2Approved drug

LabelA dazed, spaced-out feeling is listed at 0.1–5%. Anxiety, low mood and irritability aren’t listed for the single IV test dose.

hCGApproved drug

LabelIrritability, restlessness and depression are listed in the US labels without rates; a UK label rates mood changes common (1–10 in 100).

L-CarnitineApproved drug

LabelDepression 5% vs 3% and anxiety 1% vs 5% on placebo in the label’s dialysis trials, so no clear effect.

LiraglutideApproved drug

LabelAnxiety 2.0% vs 1.6% on placebo in adults; depression 4% vs 2.4% in teens. FDA removed Saxenda’s suicidal-thoughts warning in 2026; its review of 91 GLP-1 trials found no rise.

Melanotan 1Approved drug

LabelThe EU label lists low mood, including depression, as uncommon (under 1 in 100), and confusion as rare. Neither is in the US label’s table.

SemaglutideApproved drug

LabelAnxiety: 4% vs 2% on placebo in the teen trial. FDA’s 2026 review of 91 GLP-1 drug trials found no rise in depression, anxiety, irritability or suicidal thoughts.

TesamorelinApproved drug

LabelDepression: 2.0% vs 1.5% on placebo in the original 2010 label. In a 20-week trial in 152 older adults, mood scores didn’t differ from placebo.

TriptorelinApproved drug

LabelDepression and mood change are common (1–10 in 100) in men, per the UK label, with rare suicidal thoughts. Children may have crying, irritability or aggression, the US label says.

TirzepatideApproved drug

LabelNot a listed side effect. Zepbound’s warning on suicidal thoughts was removed in 2026, after FDA’s review of 91 GLP-1 drug trials found no rise in them or in depression.

SermorelinHuman studies

LabelMood changes weren’t listed; hyperactivity occurred in under 1% of 350 patients in the Geref trials, mostly children.

From human studies 13

What published trials and case reports found.

DSIPApproved drug

TrialSmall open studies reported better mood. In a 107-person IV withdrawal study, anxiety eased more slowly than other symptoms and came back in some after treatment ended.

MazdutideApproved drug

TrialIn a 24-week phase 2 trial of 248 Chinese adults, depression and suicidal-thought questionnaires showed no link; people with moderate to severe depression or past suicidal thoughts were excluded.

OxytocinApproved drug

TrialIn a 24-week nasal trial, irritability (13.7% vs 13.9%) and anxiety (4.1% vs 5.6%) matched placebo; restlessness was higher (7.5% vs 2.1%).

AOD9604Human studies

TrialMild to moderate euphoria, judged possibly related, in 5 of 23 men during IV infusions, none on placebo. Depression scores didn’t change in a 4-week oral pain trial.

ARA-290Human studies

TrialLow mood in 1 of 46 people and agitation in 1 of 46, vs tearfulness in 1 of 16 on placebo. One person on 8 mg reported suicidal thoughts.

Melanotan 2Human studies

TrialA man who injected 6 mg had anxiety and agitation needing sedatives, with a racing heart (case report). Mood wasn’t assessed in the small trials.

MK-677Human studies

TrialAgitation and confusion were among drug-related side effects more common than on placebo in people with Alzheimer’s disease. Mood in healthy users hasn’t been studied.

NAD+Human studies

TrialIn a review of 10 oral NADH and precursor trials (489 people), side effects were mild and one trial reported less anxiety. Injected NAD+ hasn’t been studied for mood.

SurvodutideHuman studies

TrialDepression was reported in 4 of 146 (2.7%) on survodutide vs none of 70 on placebo in SYNCHRONIZE-MASLD; suicidal thoughts in none vs 2. Numbers are small.

TesofensineHuman studies

TrialMood changes increased at 1.0 mg in the obesity trial. In 52 recreational stimulant users, a single dose felt no different from placebo on drug-liking scales.

Thymosin Beta-4Human studies

TrialIsolated reports: depression in 1 of 55 and 1 of 53 people on the gel in two ulcer trials, and 1 of 10 on eye drops, vs none on placebo.

Follistatin-344Preclinical

TrialIn the 3-boy Duchenne gene-therapy trial, 1 had anxiety and 1 had agitation or behavior changes, without a control group. No data for injected follistatin.

GlutathioneApproved drug

TrialNot listed in the Italian label. In a 151-patient cisplatin trial, depression scores were better with glutathione than without.

From user reports 2

Commonly reported by people who use it, not established in a study.

SemaxApproved drug

CommunityUsers report anxiety, irritability or overstimulation. The Russian labels list no mood side effects but rule it out in anxiety disorders and acute psychosis.

PE-22-28Preclinical

CommunityUsers report restlessness or anxiety at higher amounts. In mice it reduced depression-like behavior; it has never been tested in people.

Studied in people, not reported 22

Labels or trials covered enough people and didn’t report it. It can still happen.

GonadorelinApproved drug

Not reportedNot listed in the UK label, which covers a single diagnostic dose.

OrforglipronApproved drug

Not reportedAnxiety and low mood aren’t listed in the label (3,155 people, up to 72 weeks). FDA’s 2026 review of 91 GLP-1 drug trials found no rise in either.

PT-141Approved drug

Not reportedAnxiety, low mood and irritability aren’t listed in the label’s 24-week trials of 627 women on it or the 52-week extension.

SelankApproved drug

Not reportedNot listed as a side effect; the drops are registered to treat anxiety and mood instability. The label says Selank isn’t habit-forming.

SS-31Approved drug

Not reportedNot a listed side effect, and not reported by 5% or more of 117 adults over 48 weeks, or by 2 or more of 30 in a 4-week trial.

ThymalinApproved drug

Not reportedNot listed in the Russian label, which names only allergic reactions; published trials, mostly small and from Russia, gave few safety details.

Thymosin Alpha-1Approved drug

Not reportedNot listed in either label. FDA’s only US report, in a man also taking peginterferon, included anxiety, which peginterferon itself can cause.

VIPApproved drug

Not reportedNot listed in Invicorp’s label. In a 196-person trial of 3-day IV infusions, no side effect type except diarrhea was more common than on placebo.

ArgirelineHuman studies

Not reportedNot reported in the small skin trials (up to 60 people, mostly 4–8 weeks); the most reliable lab tests found almost none reaches deeper skin.

CagrilintideHuman studies

Not reportedAnxiety or low mood weren’t among common side effects (5% or more) in the 26-week trial of 506 people on cagrilintide alone.

CJC-1295 with DACHuman studies

Not reportedNot among the side effects FDA summarized from the published trials (63 healthy adults, up to 49 days).

GHK-CuHuman studies

Not reportedNot reported in the small topical studies (13–86 people, mostly 8–12 weeks), which gave few safety details. Injection hasn’t been studied in people.

GHRP-6Human studies

Not reportedNot reported in single-dose studies of hundreds of people. It raises cortisol, a stress hormone, but effects on mood haven’t been measured.

HexarelinHuman studies

Not reportedNot reported in small studies. IV doses briefly raise cortisol, a stress hormone, but 16 weeks of injections didn’t raise 24-hour cortisol output.

IpamorelinHuman studies

Not reportedNot among the side effects reported from the IV studies (40 healthy men, one dose; 56 surgery patients, up to 7 days).

Kisspeptin-10Human studies

Not reportedNot reported in small, short human studies (about 300 people, single doses to 12 days), which often didn’t track side effects.

LarazotideHuman studies

Not reportedNot more common than on placebo in a pooled analysis of four trials (626 people with celiac disease, up to 12 weeks).

LL-37Human studies

Not reportedNot among the side effects reported in the ulcer trials (about 200 people, up to 13 weeks), which applied it to wounds.

MatrixylHuman studies

Not reportedNot reported in the skin trials (93 women for 12 weeks; 196 using a mix for 8 weeks), where it was well tolerated.

RetatrutideHuman studies

Not reportedAnxiety or low mood wasn’t among side effects reported in 5% or more of 338 adults in the 48-week phase 2 trial. Phase 3 psychiatric data aren’t in published abstracts.

SNAP-8Human studies

Not reportedNot reported in two small patch studies that mixed it with other actives (24 people for 28 days; another for 12 weeks); SNAP-8 alone hasn’t been studied.

BPC-157Preclinical

Not reportedNot reported in the small human studies (about 80 people, one dose to 2 weeks of use), which gave few safety details.

No human safety data 19

No one has been given it in a published study, so it can’t be ruled in or out.

DihexaHuman studies

No dataNo human data for dihexa itself; its prodrug’s trials excluded people with severe depression or major psychiatric disorders, so effects on mood are unknown.

5-Amino-1MQPreclinical

No dataNo human safety data: no published study has given it to a person.

AdamaxPreclinical

No dataNo safety data for Adamax. Semax’s Russian labels rule it out in anxiety disorders and acute psychosis, and Semax users report overstimulation.

AHK-CuPreclinical

No dataNo human safety data: AHK-Cu has never been tested in people, on the skin or by injection.

CartalaxPreclinical

No dataNo human data: no study of cartalax in people has been published, so side effects are unknown.

CJC-1295 (no DAC)Preclinical

No dataNo human safety data for this peptide.

EpithalonPreclinical

No dataNo human safety data: FDA found no study that assessed safety, and its one placebo-controlled trial (40 women, 20-day spray) didn’t report side effects.

FOXO4-DRIPreclinical

No dataNo human data: no one has been given FOXO4-DRI in a published study, so side effects are unknown.

HGH Fragment 176-191Preclinical

No dataNo human safety data for this peptide.

HumaninPreclinical

No dataNo human data: no one has been given humanin or its stronger version HNG in a published study, so side effects are unknown.

IGF-1 DESPreclinical

No dataNo human safety data exist for IGF-1 DES. Confusion or irritability can be signs of low blood sugar, its main expected risk.

IGF-1 LR3Preclinical

No dataNo human safety data exist for IGF-1 LR3. Confusion or irritability can be signs of low blood sugar, its main expected risk.

KPVPreclinical

No dataNo human safety data: FDA’s 2026 review found no study and no adverse-event report for KPV by any route.

MGFPreclinical

No dataNo human safety data: no published study has given MGF to a person.

MOTS-cPreclinical

No dataNo human safety data for MOTS-c itself. In a 4-week trial of a modified version, CB4211, injection-site reactions were the only side effect in over 10% of the 11 treated.

PEG-MGFPreclinical

No dataNo human safety data: FDA found no human exposure data for PEG-MGF by any route.

PinealonPreclinical

No dataNo useful human safety data: the few small Russian reports on pinealon gave no details of side effects.

SLU-PP-332Preclinical

No dataNo human safety data: no published study has given it to a person.

TB-500Preclinical

No dataNo human safety data: FDA found no study that has given TB-500 to a person.

Sources

Each answer comes from the compound’s own page, under “Can it cause …?”, where its sources are listed.