SHLPs (small humanin-like peptides)

Six peptides with different identities. SHLP means small humanin-like peptide: short amino-acid chains identified in mitochondrial DNA's 16S rRNA region, beside humanin. SHLP2 has 26 amino acids; SHLP6 has 20. Humanin, its HNG variants, MOTS-c and synthetic SS-31 are separate compounds, even when guides group them together. Cobb et al.: naturally occurring mitochondrial-derived peptides (Animal context · Accessed 2026-09-30)

SHLPs are six small mitochondrial peptides discussed for cellular resilience, metabolism and aging. SHLP2 attracts practical interest; SHLP6 has different experimental effects. Accessible discussion is mostly charts and research commentary. Original accounts include subtle energy and no obvious change; human benefit, timing and safety remain unresolved.

Completing a mitochondrial stack is part of the appeal. Preserved discussion places SHLP2 beside humanin, MOTS-c and SS-31 for complementary cell-protection and energy stories. Calling it a fourth pillar organizes those hopes; it does not establish that combining them improves health.

Charts are more available than complete user stories. The opened guides lack dose-linked personal outcomes. PeptaBase displays zero approved SHLP6 feedback submissions. The Longevity Archive's report counters lack individual trails and cannot become six verified users; its broad statements denying any human use also exceed the evidence. PeptaBase: SHLP6 protocol and research feedback (Community guide · Accessed 2026-09-30) · The Longevity Archive: SHLP2 discussion summary (Secondhand community claim · Accessed 2026-09-30)

Source context — Cobb et al.: naturally occurring mitochondrial-derived peptides: Cell cultures, rats and mice, not exogenous human efficacy or safety. Model-specific apoptosis effects do not prove universal SHLP6 harm or selective killing of cancer cells. Some authors disclosed CohBar stock/consulting interests.

Source context — PeptaBase: SHLP6 protocol and research feedback: No first-person submissions displayed; no human course, PK or duration. Page lists 2016 as most recent study despite accessible 2025 fish work. Zero approved feedback describes this page only, not all SHLP users.

Source context — The Longevity Archive: SHLP2 discussion summary: No individual energy reports inspected or deduplicated. Page's six-effects counter is not six verified users; categorical claims that no human has ever received SHLP2 exceed a no-published-trial finding. Its generic purported unwanted effects are cautions, not an adverse-event case series.

Energy and recovery are the anecdotal themes. Original notes mention subtle energy, recovery and metabolic steadiness, alongside little or no early effect. The Longevity Archive repeats energy reports without individual links. Neither account establishes frequency or whether SHLP caused the change. The Longevity Archive: SHLP2 discussion summary (Secondhand community claim · Accessed 2026-09-30)

First-week and week-one-to-two accounts differ. Preserved anecdotes include no distinct day-one or first-week change and occasional energy or recovery during weeks one to two. Amount, route and same-person follow-up are missing. Injection sting or warmth is not evidence of a mitochondrial benefit.

Weight, vision and brain protection are research-led hopes. Biohacking commentary borrows these goals from mouse metabolism, eye-cell experiments and genetic or toxin-model work. Mouse protection from a high-fat diet and Parkinson's research are not demonstrated human treatment outcomes. Kim et al.: SHLP2 regulates energy homeostasis through hypothalamic neurons (Animal context · Accessed 2026-09-30) · Kim et al.: naturally occurring SHLP2 variant and Parkinson's disease (Animal context · Accessed 2026-09-30)

Source context — The Longevity Archive: SHLP2 discussion summary: No individual energy reports inspected or deduplicated. Page's six-effects counter is not six verified users; categorical claims that no human has ever received SHLP2 exceed a no-published-trial finding. Its generic purported unwanted effects are cautions, not an adverse-event case series.

Source context — Kim et al.: SHLP2 regulates energy homeostasis through hypothalamic neurons: Intervention findings concern male mice and laboratory routes. Human serum associations do not establish injected benefit. Appetite-endpoint windows are not plasma elimination or community human felt duration.

Source context — Kim et al.: naturally occurring SHLP2 variant and Parkinson's disease: Human genetics plus preclinical intervention. No human injection PK or treatment outcome. Retail SHLP2 sequence cannot be inferred from the paper; full numerical PK or dose-comparison result not adopted from uninspected sections.

SHLP2: 50–200 mcg versus 0.5–2 mg per injection. Peptide Hub lists 50–200 mcg SC every other day or three times weekly. The Compound Report instead gives 0.5–2 mg SubQ weekly or two to three times weekly. Keep these separate: neither page supplies individual logs behind its band, and their amounts differ substantially. Peptide Hub: SHLP2 research profile and chart (Community guide · Accessed 2026-09-30) · The Compound Report: SHLP2 Community Use (Secondhand community claim · Accessed 2026-09-30)

SHLP6: 50–150 mcg per injection. Peptide Hub's separate SHLP6 page lists SC every other day or three times weekly and a 2 mg vial. This matches the preserved retail-chart amount, without proving that page was its original source. Vial contents are not a daily dose; this SHLP6 band is not a SHLP2 band. Peptide Hub: SHLP6 research profile and chart (Community guide · Accessed 2026-09-30)

Other guides leave dose and frequency unestablished. CalcMyPeptide supplies no established human dose; its calculator example is not validation. These reference-site claims do not establish multi-forum consensus. Mouse mg/kg injections and brain infusions cannot supply missing human amounts. CalcMyPeptide: SHLP2 dosing guide (Community guide · Accessed 2026-09-30)

Source context — Peptide Hub: SHLP2 research profile and chart: Author-created commercial chart, not independent first-person dosing logs. Identity prose incorrectly calls SHLP2 a 20-amino-acid 12S-region peptide; those errors are not adopted. No human timing evidence attached.

Source context — The Compound Report: SHLP2 Community Use: No linked individual report underlying the claimed community band; not an observed user distribution. Other page claims include inconsistent evidence counters and incorrect author/group attribution for the 2023 paper. Only its attributed dosing claim is used.

Source context — Peptide Hub: SHLP6 research profile and chart: Promotional guide, not a user course or human dose study. Incorrect 12S origin and unsupported broad cancer-selectivity language are not adopted. Matching old numbers does not establish historical source lineage.

Source context — CalcMyPeptide: SHLP2 dosing guide: Editorial reference, not a person reporting use. Its linked PMID 26718411 does not match the foundational SHLP paper PMID 27070352. Calculator illustration does not supply human dose evidence. Food timing and regulatory assurances not adopted.

First-week and week-one-to-two accounts differ. Preserved anecdotes include no distinct day-one or first-week change and occasional energy or recovery during weeks one to two. Amount, route and same-person follow-up are missing. Injection sting or warmth is not evidence of a mitochondrial benefit.

Four to eight weeks is a guide expectation. Peptide Hub's SHLP2 page claims effects become measurable after four to eight weeks, without supporting human measurements. Waiting longer is not a demonstrated solution to nonresponse. Peptide Hub: SHLP2 research profile and chart (Community guide · Accessed 2026-09-30)

A single-dose felt window is unknown. The preserved account does not connect a known injection to a same-person rise and fade. PeptaBase leaves human duration unestablished. Weeks of use cannot tell us whether noticed changes persist for hours, days or after stopping. PeptaBase: SHLP6 protocol and research feedback (Community guide · Accessed 2026-09-30)

Unknown is the useful answer here. CalcMyPeptide calls SHLP2's half-life unknown; PeptaBase leaves SHLP6 kinetics poorly characterized. Morning habits, every-other-day charts and borrowed humanin estimates do not measure human SHLP clearance. CalcMyPeptide: SHLP2 dosing guide (Community guide · Accessed 2026-09-30) · PeptaBase: SHLP6 protocol and research feedback (Community guide · Accessed 2026-09-30)

K4R is a sequence variant, not a longer-lasting retail promise. The 2024 study linked an inherited K4R-SHLP2 variant with lower Parkinson's risk and greater experimental stability, alongside cell and mouse protection. That does not measure the half-life of a human injection or show that a vial marked SHLP2 contains K4R. Genetic association and exogenous treatment answer different questions. Kim et al.: naturally occurring SHLP2 variant and Parkinson's disease (Animal context · Accessed 2026-09-30)

Source context — Peptide Hub: SHLP2 research profile and chart: Author-created commercial chart, not independent first-person dosing logs. Identity prose incorrectly calls SHLP2 a 20-amino-acid 12S-region peptide; those errors are not adopted. No human timing evidence attached.

Source context — PeptaBase: SHLP6 protocol and research feedback: No first-person submissions displayed; no human course, PK or duration. Page lists 2016 as most recent study despite accessible 2025 fish work. Zero approved feedback describes this page only, not all SHLP users.

Source context — CalcMyPeptide: SHLP2 dosing guide: Editorial reference, not a person reporting use. Its linked PMID 26718411 does not match the foundational SHLP paper PMID 27070352. Calculator illustration does not supply human dose evidence. Food timing and regulatory assurances not adopted.

Source context — Kim et al.: naturally occurring SHLP2 variant and Parkinson's disease: Human genetics plus preclinical intervention. No human injection PK or treatment outcome. Retail SHLP2 sequence cannot be inferred from the paper; full numerical PK or dose-comparison result not adopted from uninspected sections.

Four-to-eight and eight-to-twelve-week conventions coexist. The original retains shorter exploratory blocks and longer vendor blocks. The reviewed Peptide Hub pages list eight to twelve weeks for SHLP2 and SHLP6. Neither calendar establishes a safe or effective human course. Peptide Hub: SHLP2 research profile and chart (Community guide · Accessed 2026-09-30) · Peptide Hub: SHLP6 research profile and chart (Community guide · Accessed 2026-09-30)

Breaks and seasonal restarts are borrowed lore. Preserved notes mention multi-week breaks after multi-month use and restarts once or a few times yearly. No reliable SHLP-specific tolerance or reset evidence accompanies them. PeptaBase supplies no human off period. PeptaBase: SHLP6 protocol and research feedback (Community guide · Accessed 2026-09-30)

Source context — Peptide Hub: SHLP2 research profile and chart: Author-created commercial chart, not independent first-person dosing logs. Identity prose incorrectly calls SHLP2 a 20-amino-acid 12S-region peptide; those errors are not adopted. No human timing evidence attached.

Source context — Peptide Hub: SHLP6 research profile and chart: Promotional guide, not a user course or human dose study. Incorrect 12S origin and unsupported broad cancer-selectivity language are not adopted. Matching old numbers does not establish historical source lineage.

Source context — PeptaBase: SHLP6 protocol and research feedback: No first-person submissions displayed; no human course, PK or duration. Page lists 2016 as most recent study despite accessible 2025 fish work. Zero approved feedback describes this page only, not all SHLP users.

The mitochondrial suite makes attribution difficult. Humanin or HNG, MOTS-c and SS-31 recur in the preserved stack discussion; NMN, NR and injectable NAD+ also appear. Some notes favor isolating SHLP2, while other charts pair SHLP2 with SHLP6. Changing sleep, food, training or several compounds together makes both improvement and adverse effects hard to assign.

MDP trio / suite: SHLP2 + humanin (or HNG) + MOTS-c is the longevity-cluster stack people name most—cytoprotection + metabolic reprogramming narrative. Ratios/doses vary; no validated combo protocol. [community]

“Fourth pillar” lore: Some research-peptide writeups cast SHLP2 as completing a suite with humanin (anti-apoptosis), MOTS-c (AMPK/metabolic), and SS-31 (membrane cardiolipin/ETC framing). Marketing taxonomy, not a clinical regimen. [community]

NAD-axis: With NMN, NR, or injectable NAD+ in energy/aging stacks—common confounding when people credit SHLP alone. [community]

SHLP6 is not automatically an extra longevity ingredient. Cobb's founding assays found increased cell death with SHLP6 where SHLP2 and SHLP3 were protective. A newer zebrafish toxicity study found protective SHLP6 effects in a different setting. Both are preclinical: neither establishes selective cancer treatment, human protection or a reason to combine isoforms. Cobb et al.: naturally occurring mitochondrial-derived peptides (Animal context · Accessed 2026-09-30) · Kannan et al.: SHLP6 in copper-induced zebrafish toxicity (Animal context · Accessed 2026-09-30)

Preference for separate SHLP2 use: Some notes favor isolating SHLP2 because SHLP6 showed opposing cell-death effects in founding assays. This is a reported concern, not proof of a safe human regimen. [community]

SHLP2 + SHLP6 “full protocol” charts: A minority of vendor tables suggest running both—biologically contested because founding assays put them on opposite apoptotic poles; treat as marketing, not consensus biology. [community]

Source context — Cobb et al.: naturally occurring mitochondrial-derived peptides: Cell cultures, rats and mice, not exogenous human efficacy or safety. Model-specific apoptosis effects do not prove universal SHLP6 harm or selective killing of cancer cells. Some authors disclosed CohBar stock/consulting interests.

Source context — Kannan et al.: SHLP6 in copper-induced zebrafish toxicity: Zebrafish embryos/larvae and cell-free assays, not humans or cancer-selectivity validation. Abstract and result details differ in some reported concentration/outcome numbers; inflammatory markers also rise. Only the model-specific protective finding is adopted.

SHLP6 is not automatically an extra longevity ingredient. Cobb's founding assays found increased cell death with SHLP6 where SHLP2 and SHLP3 were protective. A newer zebrafish toxicity study found protective SHLP6 effects in a different setting. Both are preclinical: neither establishes selective cancer treatment, human protection or a reason to combine isoforms. Cobb et al.: naturally occurring mitochondrial-derived peptides (Animal context · Accessed 2026-09-30) · Kannan et al.: SHLP6 in copper-induced zebrafish toxicity (Animal context · Accessed 2026-09-30)

Adverse-event rates and product identity remain unresolved. Original cautions include local redness, itch and irritation, infection or contamination concerns, and wrong-sequence or wrong-isoform products. These are practical warnings, not verified SHLP-specific incidence figures. An unlabeled blend conceals component amounts; a research label alone does not establish identity, purity or sterility.

Cancer and glucose discussions are theoretical cautions. Preserved talk questions survival signaling in people with cancer histories and glucose effects alongside diabetes medicines. It supplies no human interaction table or demonstrated clinical risk rate. Pregnancy, chronic use and exogenous-human safety also remain unanswered in the inspected material; sparse complaints cannot establish safety.

Source context — Cobb et al.: naturally occurring mitochondrial-derived peptides: Cell cultures, rats and mice, not exogenous human efficacy or safety. Model-specific apoptosis effects do not prove universal SHLP6 harm or selective killing of cancer cells. Some authors disclosed CohBar stock/consulting interests.

Source context — Kannan et al.: SHLP6 in copper-induced zebrafish toxicity: Zebrafish embryos/larvae and cell-free assays, not humans or cancer-selectivity validation. Abstract and result details differ in some reported concentration/outcome numbers; inflammatory markers also rise. Only the model-specific protective finding is adopted.