25C-NBOH

# Research Output: 25C-NBOH

## Chemical Identity

**PubChem CID:** 125181419 (confirmed via PubChem API lookup [Ref — database_lookup]) [Ref 1]
**Molecular Formula:** C₁₇H₂₀ClNO₃
**Molecular Weight:** 321.8 g/mol
**IUPAC Name:** 2-[[2-(4-chloro-2,5-dimethoxyphenyl)ethylamino]methyl]phenol
**Systematic name (seed data match):** 2-[[2-(4-chloro-2,5-dimethoxyphenyl)ethylamino]methyl]phenol — **confirmed match**
**InChIKey:** VHWXICYYQMMZCW-UHFFFAOYSA-N
**CAS number (hydrochloride salt):** 1539266-20-0 (per Cayman Chemical reference standard [Ref 25])
**SMILES:** Not returned in PubChem API response; should be retrieved independently.

**Seed data discrepancies:**
- The brief listed SMILES, molecular formula, molecular weight, InChIKey, and PubChem CID as blank. All have now been confirmed via PubChem (CID 125181419). **FLAG: These fields should be populated in the DB.**
- PubChem returned MW 321.8, consistent with C₁₇H₂₀ClNO₃.

**Structural context:** 25C-NBOH (also written 2C-C-NBOH or NBOH-2C-C) belongs to the 25x-NBOH series — the N-(2-hydroxybenzyl) analogues of the 2C-X phenethylamine psychedelics. It is structurally related to 25C-NBOMe, differing only in the benzyl substituent: NBOH carries a free 2-hydroxyl group (phenol) rather than the 2-methoxy group of NBOMe. This structural difference has significant pharmacokinetic and physicochemical implications (lower lipophilicity, different metabolic pathways, greater pH-dependent ionization at the phenol). 25C-NBOH is also the principal O-demethylation metabolite of 25C-NBOMe (Kristofic et al. 2016 [Ref 6]; Caspar et al. 2016 [Ref — see note]).

---

## Pharmacology

### Primary Receptor Target
25C-NBOH acts as a potent agonist at the serotonin 5-HT₂A receptor, the primary target mediating its psychedelic effects (Poulie et al. 2020 [Ref 4]; Zawilska et al. 2020 [Ref 2]). Agonism at 5-HT₂C receptors is also expected based on the class SAR (Eshleman et al. 2018 [Ref 7]).

### Receptor Binding Data

**No published receptor binding affinity (Ki) values are available specifically for 25C-NBOH.** The following data are from closely related NBOH-class compounds and the systematic SAR study that defines the class:

- **Hansen et al. (2014)** conducted the seminal 48-compound SAR study of N-benzyl phenethylamines at 5-HT₂A/2C receptors [Ref 22]. The NBOH scaffold (2'-OH benzyl group) was among substituents tested. Across the 48-compound series, 5-HT₂A binding affinities ranged from subnanomolar (best: 0.29 nM for compound 8b) to micromolar. The most potent functional agonist in the series had an EC₅₀ of 0.074 nM at 5-HT₂A. Most compounds showed low-to-moderate selectivity (1–40-fold) for 5-HT₂A over 5-HT₂C.

- **Eshleman et al. (2018)** characterized NBOH-class compounds (including 25I-NBOH) at 5-HT₁A, 5-HT₂A, 5-HT₂B, and 5-HT₂C receptors [Ref 7]. 25I-NBOH showed very high affinity for 5-HT₂A and 5-HT₂C (subnanomolar to low nanomolar), full efficacy at both receptors, very low potency at 5-HT₁A, lower affinity at 5-HT₂B, and negligible activity at monoamine transporters (low-to-mid micromolar). The pharmacology was described as "consistent with hallucinogenic activity, with little psychostimulant activity."

- **Pottie et al. (2020)** identified biased agonism within the NBOH class at 5-HT₂A, specifically for the 25H-NBOH analogue (the unsubstituted phenethylamine variant), which showed statistically significant preference for β-arrestin 2 recruitment over miniGαq compared to LSD reference [Ref 3]. The authors note that Gq-signaling bias is the proposed driver of psychedelic effects (Wallach et al. 2023 [Ref 14]).

- **Wallach et al. (2023)** established that 5-HT₂A Gq-signaling (not β-arrestin 2) efficacy predicts psychedelic potential as measured by mouse head twitch response magnitude [Ref 14]. β-arrestin-biased ligands blocked psychedelic effects and induced receptor tachyphylaxis. This framework is relevant for understanding why 25C-NBOH is considered psychedelically active despite some class-level β-arrestin bias.

### Mechanism of Action
As a 5-HT₂A agonist, 25C-NBOH activates Gq protein-coupled signaling leading to phospholipase C activation, IP₃ production, intracellular Ca²⁺ mobilization, and downstream gene expression changes (Poulie et al. 2020 [Ref 4]; Wallach et al. 2023 [Ref 14]). The compound is also expected to activate 5-HT₂C receptors, contributing to sympathomimetic and other physiological effects (Eshleman et al. 2018 [Ref 7]).

**FLAG for generation agent:** No substance-specific Ki or EC₅₀ values for 25C-NBOH exist in the published literature. All receptor pharmacology data above derives from class-level inference. The generation agent should state this clearly.

### Pharmacokinetics

**No published human pharmacokinetic studies exist for 25C-NBOH.**

By class-level inference from 25I-NBOH (the most-studied NBOH analogue):
- **Metabolism:** Nielsen et al. (2017) studied the CYP metabolism of 25I-NBOH in human liver microsomes [Ref 5]. The major CYP enzyme for 25I-NBOH was **CYP2D6** (contrasting with 25I-NBOMe, which is primarily CYP3A4). Metabolic pathways include hydroxylation, O-demethylation, N-dealkylation, dehydrogenation, and combinations thereof. Intrinsic clearance (CLint) for 25I-NBOH was 118.7 mL/min/kg. **25I-NBOH was also liable to direct glucuronidation**, which may diminish the impact of CYP2D6 genetic polymorphism. For 25C-NBOH, by structural analogy, CYP2D6 is the likely primary metabolic enzyme, with direct glucuronidation as an additional pathway.

- **Route of administration:** Sublingual is the primary route documented in forensic cases and seized sample characterizations (Machado et al. 2019 [Ref 1]). Sublingual administration of the free base/phenol form allows absorption through the oral mucosa, bypassing first-pass hepatic metabolism.

- **Duration:** The seed data (5–7 hours total duration, 15–45 min onset) is consistent with published reports for 25I-NBOH and the broader NBOH class. No controlled human studies confirm these values; they derive from user reports.

- **Bioavailability, Tmax, volume of distribution:** No published data for 25C-NBOH or any NBOH compound in humans.

**FLAG:** All PK data are structural analog inferences from 25I-NBOH, except where stated.

---

## History

### Discovery and Synthesis
The NBOH class of compounds was developed at the **University of Copenhagen** by **Martin Hansen, Jesper L. Kristensen**, and colleagues as part of a systematic medicinal chemistry programme to characterize structure-activity relationships of N-benzyl phenethylamine agonists at serotonin 5-HT₂A/2C receptors (Hansen et al. 2014 [Ref 22]; Hansen et al. 2015 [Ref 23]). The 2'-hydroxybenzyl (NBOH) scaffold emerged as a key variant alongside the 2'-methoxybenzyl (NBOMe) scaffold, and was found to confer high receptor affinity.

The broader N-benzyl phenethylamine class (NBOMes) was first reported by **Ralf Heim et al. (2002)** in a German patent, and later characterized pharmacologically in peer-reviewed publications (Poulie et al. 2020 [Ref 4]). The specific NBOH subfamily — using an ortho-hydroxy rather than ortho-methoxy benzyl group — was developed specifically as part of research aimed at optimizing 5-HT₂A receptor pharmacological tools, culminating in the highly selective 25CN-NBOH (Märcher-Rørsted et al. 2021 [Ref 26]).

25C-NBOH specifically has not been assigned a precise year of first synthesis in any accessible published source. It is known to have appeared on the NPS/research chemical market by approximately 2014–2017, based on seizure records in Brazil (Machado et al. 2019 [Ref 1]).

### Market Emergence
The first published forensic identification of 25C-NBOH in seized samples is **Machado et al. (2019)** [Ref 1], who identified 25B-NBOH, 25C-NBOH, and 25E-NBOH in blotter papers seized between 2017 and 2018 by Brazilian law enforcement. The authors note that NBOH substances had become the dominant hallucinogenic drugs identified in seized blotter papers in the region between 2014 and early 2019, supplanting both LSD and NBOMe compounds. This regional dominance in Brazil reflects both the non-scheduled status of NBOHs in most jurisdictions and active substitution dynamics in the NPS market.

25C-NBOH is also documented as the principal O-demethylation metabolite of 25C-NBOMe (Kristofic et al. 2016 [Ref 6]; Andreasen et al. 2015 [Ref 9]). This metabolic relationship means it can appear in forensic samples as evidence of 25C-NBOMe ingestion, complicating attribution.

25I-NBOH was first identified in seized Brazilian blotter papers in 2016 (Arantes et al. 2017 [Ref 8]), and the NBOH class (25B, 25C, 25E variants) was characterized in 2019 (Machado et al. 2019 [Ref 1]).

### Regulatory History
- **UN Conventions:** No NBOH compounds, including 25C-NBOH, are listed under any UN drug control conventions as of the time of the Machado et al. 2019 study [Ref 1].
- **United Kingdom:** NBOMe compounds were placed under Class A of the Misuse of Drugs Act 1971 by the 2014 Amendment Order (Home Office Circular 008/2014 [Ref 31]). Whether 25C-NBOH (an NBOH, not an NBOMe) falls within this generic definition is not unambiguously confirmed in published sources. The UK Psychoactive Substances Act 2016 would also apply, banning all psychoactive substances not otherwise exempted.
- **Brazil:** NBOH compounds, including 25C-NBOH, were scheduled in Brazil in December 2018 per Brazilian NPS legislative updates (Santos et al. 2023 [Ref — web retrieved]).
- **United States:** 25C-NBOMe (the methoxy variant) was permanently placed in DEA Schedule I in 2013. 25C-NBOH is not directly scheduled at the federal level but may constitute a Controlled Substance Analogue when intended for human consumption. Louisiana specifically listed 25I-NBOH as Schedule I as of June 2013 (Erowid NBOMe legal database [web retrieved]).

**FLAG for generation agent:** Legal status of 25C-NBOH requires careful jurisdictional distinction from 25C-NBOMe. The NBOH and NBOMe variants are structurally different (OH vs OMe) and may have different scheduling status in each jurisdiction. Confirm legal status via current official sources before publishing.

---

## Subjective Effects

No controlled human studies of 25C-NBOH exist. The following is drawn from forensic case reports, class-level evidence from closely related NBOMe and NBOH compounds, and user-report-only sources.

**PRIMARY SOURCES NOTE:** All effect data below is either (a) class-level inference from the NBOMe/NBOH literature, (b) from the single 25C-NBOH forensic case data, or (c) from user reports. There are no controlled human trials.

### Documented effects (class-level evidence from NBOMe literature)
Zawilska et al. (2020) [Ref 2] compiled adverse effects across NBOMe compounds from published clinical intoxication reports and forensic cases. Commonly observed effects include:
- **Perceptual:** Visual and auditory hallucinations, geometry, color enhancement, tracers
- **Cognitive/affective:** Confusion, anxiety, panic and fear, euphoria at lower doses
- **Behavioral:** Agitation, uncontrollable violent behavior at high/toxic doses
- **Autonomic/sympathomimetic:** Mydriasis (pupil dilation), tachycardia, hypertension, hyperthermia, diaphoresis

Severe toxic effects documented in NBOMe case series (Gee et al. 2016 [Ref 12]; Kyriakou et al. 2015 [Ref 13]):
- Seizures, excited delirium, rhabdomyolysis, disseminated intravascular coagulation, hypoglycemia, metabolic acidosis, multiorgan failure

### Duration
The seed data entries (total 5–7 hours, onset 15–45 min, come-up 30–90 min, aftereffects 3–6 days) are sourced from user reports and have not been confirmed in controlled studies. These are within the range of reported durations for NBOH class compounds and are plausible by analogy but represent **user-report-only data**.

The extended aftereffect period (3–6 days) is particularly notable and may reflect persistent 5-HT₂A receptor downregulation and/or psychological integration effects. **FLAG:** This value has not been confirmed in any published pharmacological study and warrants editorial review.

### Dose
The seed data dose ranges (threshold 100 µg, light 250–500 µg, common 500–750 µg, strong 750–1000 µg, all sublingual) are user-report-only. They are generally consistent with the potency of the NBOH class relative to NBOMes (which are active at similar microgram doses). **FLAG:** No controlled dosing study exists for 25C-NBOH. These values should be labeled as user-report data.

---

## Safety & Toxicity

### 25C-NBOH-Specific Cardiotoxicity (Direct Study)
**Yoon et al. (2022)** is the only published pharmacological/toxicological study directly investigating 25C-NBOH [Ref 19]:
- **In vitro (MTT assay):** Treatment with 25C-NBOH "dramatically decreased viability of H9c2 cardiomyocytes."
- **In vivo (rat ECG):** 25C-NBOH significantly increased QT intervals and RR intervals.
- **PAK1:** Unlike 25I-NBOH, 25C-NBOH had no effect on PAK1 protein expression in H9c2 cells, suggesting a partially different cardiotoxic mechanism.
- **hERG assay:** 25I-NBOH inhibited hERG potassium channels; the paper does not report specific hERG data for 25C-NBOH.
- **Conclusion:** Both 25I-NBOH and 25C-NBOH may have adverse cardiovascular effects; the study characterizes QT prolongation and cardiomyocyte toxicity directly for 25C-NBOH (animal/in vitro data only).

### 25C-NBOMe (Structural Analogue) Fatality and Toxicity Data
Because 25C-NBOH is both a metabolite and structural analogue of 25C-NBOMe, and because the two compounds have identical phenethylamine cores, the safety data from 25C-NBOMe fatality cases is the best available class-level evidence:

- **Andreasen et al. (2015)** [Ref 9]: First fatal poisoning quantifying 25C-NBOMe. Young male died 12 hours after ingestion with signs of serotonin toxicity. Blood concentration 0.81 µg/kg ante-mortem. UPLC-HRTOF-MS identified 25C-NBOMe and demethylated/glucuronidated metabolites (25C-NBOH would be among these).
- **Morini et al. (2017)** [Ref 10]: Teenager drowned after becoming agitated and confused following 25C-NBOMe and 25H-NBOMe ingestion. 25C-NBOMe 2.80 ng/mL peripheral blood; levels "considered potentially toxic."
- **Kristofic et al. (2016)** [Ref 6]: Death associated with 25C-NBOMe; **25C-NBOH explicitly detected in blood and urine** alongside 25C-NBOMe, confirming in vivo human exposure to 25C-NBOH as a metabolite. Tissue distribution documented.

### Adverse Effects Profile (Class-Level)
From NBOMe intoxication case series (Gee et al. 2016 [Ref 12]; Tang et al. 2014 [Ref 11]; Zawilska et al. 2020 [Ref 2]):
- **Cardiovascular:** Tachycardia, hypertension, QT prolongation, vasoconstriction, arrhythmia risk
- **Neurological:** Seizures (documented in multiple cases), excited delirium
- **Metabolic:** Hyperthermia, rhabdomyolysis (myoglobinuria, elevated CK), acute kidney injury
- **Hematologic:** Disseminated intravascular coagulation (DIC)
- **Psychiatric:** Paranoia, agitation, violence — Gee et al. 2016 [Ref 12] found 7/10 patients required benzodiazepine sedation; peak plasma 0.7–10.1 ng/mL in clinical cases

### Toxicity Classification (Seed Data Assessment)
The seed data categorizes acute toxicity as **"high"** and chronic toxicity as **"high"**, with a note that 25C-NBOH is "potentially fatal at heavy dosages." This is consistent with published evidence from 25C-NBOMe fatality cases [Refs 9, 10] and the specific cardiotoxicity data for 25C-NBOH [Ref 19]. **However, no published LD₅₀ or therapeutic index data exist for 25C-NBOH.** These values cannot be confirmed numerically and should be flagged as extrapolated from class data.

**FLAG — Safety-critical:** The "potentially fatal at heavy dosages" designation is supported by class-level evidence but NOT by any published fatal overdose case specifically attributing death to 25C-NBOH itself (as opposed to 25C-NBOMe). This distinction should be noted in the article.

---

## Harm Reduction

### Identification and Testing
The NBOH class (including 25C-NBOH) presents significant analytical challenges:
- **GC-MS:** NBOHs are thermolabile under gas chromatographic conditions, leading to decomposition and potential misidentification as their 2C-X parent compounds (Machado et al. 2019 [Ref 1]). LC-based methods are required for reliable identification.
- **Electrochemical detection:** A validated 3D-printed electrochemical double cell has been developed for selective detection of NBOHs vs. NBOMes vs. LSD in seized samples (Melo et al. 2024 [Ref 27]).
- **Point-of-care immunoassay:** Standard immunoassay drug screens do not detect NBOMe or NBOH compounds reliably (Kyriakou et al. 2015 [Ref 13]).
- **Drug checking:** Harm reduction services should be aware that NBOH compounds are frequently found in blotter papers sold as LSD or NBOMe analogues (Machado et al. 2019 [Ref 1]).

### Dose Uncertainty Risk
A key harm reduction concern is the extreme potency of the NBOH class at microgram doses. Errors in weighing or dosing carry a high risk of severe toxicity.

### Emergency Response
Based on clinical management guidelines derived from NBOMe toxicity case series (Gee et al. 2016 [Ref 12]):
- Supportive care is the primary management approach
- Benzodiazepines (in high doses) to control agitation
- Active cooling for hyperthermia
- Monitoring for rhabdomyolysis and kidney injury
- ICU monitoring for cardiac arrhythmia given QT prolongation data [Ref 19]

---

## Tolerance & Dependence

### Tolerance
Seed data states tolerance builds "almost immediately after ingestion" with a half-life of 1 week and full reset at 2 weeks. These values are consistent with published observations for classic serotonergic psychedelics and the NBOH class. The mechanism is likely rapid 5-HT₂A receptor downregulation and desensitization following agonist exposure (Wallach et al. 2023 [Ref 14]; Poulie et al. 2020 [Ref 4]). **No published study has directly measured tolerance parameters for 25C-NBOH.**

Cross-tolerance with other serotonergic psychedelics (LSD, psilocybin, other NBOMes/NBOHs) is expected based on shared 5-HT₂A receptor mechanisms (class inference; no substance-specific data).

### Dependence
Seed data states 25C-NBOH is "not habit-forming." Classic serotonergic psychedelics generally have low dependence liability based on lack of reward circuit activation. The Eshleman et al. 2018 [Ref 7] data showing negligible monoamine transporter activity is consistent with low stimulant-type abuse potential. **No published dependence studies for 25C-NBOH exist.**

---

## Interactions

### Tramadol — Dangerous Interaction (Seed Data)
The seed data flags a **dangerous** interaction between 25C-NBOH and tramadol. This is pharmacologically well-supported:

Tramadol inhibits serotonin (and norepinephrine) reuptake and has weak µ-opioid agonist activity. Co-administration with a potent 5-HT₂A agonist substantially elevates central serotonergic tone, creating risk of serotonin syndrome (Beakley et al. 2015 [Ref 17]). Serotonin syndrome presents as a triad of neuromuscular excitation (clonus, hyperreflexia, myoclonus, rigidity), autonomic dysfunction (hyperthermia, tachycardia, diaphoresis), and altered mental status (Isbister et al. 2007 [Ref 18]). Severe cases involve rapid-onset hyperthermia, muscle rigidity, and multiorgan failure.

**Assessment:** The "dangerous" severity rating for the tramadol interaction is well-supported by pharmacological mechanism. The combination of a SERT-inhibiting opioid with a potent 5-HT₂A full agonist creates additive serotonergic load. **This is a safety-critical value confirmed by mechanistic evidence.**

### Cannabis — Unknown Interaction (Seed Data)
The seed data lists the cannabis interaction as "unknown." No published studies document the specific pharmacodynamic interaction between 25C-NBOH and cannabinoids. Cannabis is commonly co-used with psychedelics and may potentiate subjective effects via CB1 receptor mechanisms that modulate glutamatergic tone in cortical circuits also engaged by 5-HT₂A agonism. **This interaction remains uncharacterized in the published literature.**

### Other Relevant Interactions (Class-Level)
- **MAO inhibitors:** Contraindicated with serotonergic drugs; risk of severe serotonin syndrome. No 25C-NBOH-specific data.
- **Serotonergic drugs (SSRIs, SNRIs, triptans):** Additive serotonin risk (Isbister et al. 2007 [Ref 18]).
- **CYP2D6 inhibitors:** By analogy with 25I-NBOH (Nielsen et al. 2017 [Ref 5]), CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, bupropion) could increase plasma levels of 25C-NBOH. CYP2D6 poor metabolizers may experience enhanced/prolonged effects.
- **Stimulants:** Hyperthermia risk is enhanced by concurrent stimulant use (class inference from NBOMe cases).

---

## Legal Status

| Jurisdiction | Status | Notes |
|---|---|---|
| United Nations | Not controlled | No NBOH compounds listed under UN Conventions (Machado et al. 2019 [Ref 1]) |
| United Kingdom | Class A (likely) | NBOMe compounds controlled under Misuse of Drugs Act via 2014 Amendment Order (Home Office Circular 008/2014 [Ref 31]); Psychoactive Substances Act 2016 also applies |
| United States | Not directly scheduled federally | 25C-NBOMe is Schedule I (2013); 25C-NBOH may be a Controlled Substance Analogue. Louisiana: 25I-NBOH specifically Schedule I (June 2013) |
| Brazil | Controlled | Scheduled December 2018 per NPS legislation |
| Australia | Variable by state | State-level analog provisions may apply (Queensland Drugs Misuse Act) |
| European Union | Variable by member state | Not under harmonized EU control; may be covered under national generic/blanket legislation in some countries |

**FLAG:** Legal status information was compiled primarily from web sources (Erowid, web searches) and the Machado 2019 paper. This information requires verification against current official sources for each jurisdiction before publication, particularly for the UK (NBOH vs NBOMe distinction) and US (Analogue Act applicability).

---

## Clinical Trials

No clinical trials involving 25C-NBOH were found on ClinicalTrials.gov. The compound has no known therapeutic development program. It functions as a pharmacological research tool (as do other NBOH compounds) but has not entered clinical investigation.

---

## Community Feedback Analysis

No community feedback was submitted in Part A2 of the brief.

---

## Gaps & Flags

### Data Gaps

1. **Substance-specific receptor binding data:** No published Ki or EC₅₀ values for 25C-NBOH at any receptor. All receptor pharmacology is inferred from class SAR (Hansen et al. 2014 [Ref 22]) and closely related NBOH analogues (Eshleman et al. 2018 [Ref 7]).

2. **Human pharmacokinetics:** No published PK data for 25C-NBOH (or any NBOH compound) in humans. Tmax, bioavailability, half-life, and volume of distribution are unknown.

3. **SMILES string:** Not returned by the PubChem API response in this research run. Should be retrieved and populated in the DB from PubChem CID 125181419.

4. **Dose/duration confirmed data:** All dose ranges and duration data are from user reports only. No controlled human or animal dosing studies exist.

5. **LD₅₀ and therapeutic index:** No published LD₅₀ data for 25C-NBOH. Acute toxicity classification ("high") is based on class-level evidence from 25C-NBOMe fatalities.

6. **Chronic toxicity:** No published chronic toxicity or organ toxicity data for 25C-NBOH.

7. **Psychological risks:** No published systematic data on psychological adverse effects (HPPD, prolonged psychosis) for 25C-NBOH specifically.

8. **Physical properties:** No published melting point, solubility, or stability data found for 25C-NBOH.

9. **Stereochemistry:** 25C-NBOH has two stereocenters (the aminomethyl carbon and potentially the phenol orientation). No published enantioselectivity data found.

10. **Metabolic pathway:** Full metabolite profile for 25C-NBOH is unpublished. Inferred from 25I-NBOH (CYP2D6-primary, with direct glucuronidation; Nielsen et al. 2017 [Ref 5]).

### Safety-Critical Flags

- **[FLAG]** The "potentially fatal at heavy dosages" characterization in the seed data is supported by class-level evidence from 25C-NBOMe fatalities, but no published fatal overdose case specifically attributes death to 25C-NBOH as the parent drug (rather than as a metabolite of 25C-NBOMe). Generation agent should note this distinction.

- **[FLAG]** Cardiotoxicity data (Yoon et al. 2022 [Ref 19]) is from animal/cell culture studies only. QT prolongation and cardiomyocyte toxicity documented in rats and H9c2 cell lines; human cardiac safety profile is unknown.

- **[FLAG]** The tramadol interaction severity is rated "dangerous" in the seed data. This is pharmacologically well-supported by mechanism (serotonin reuptake inhibition + 5-HT₂A agonism = serotonin syndrome risk) but no case reports specifically documenting this combination with 25C-NBOH were found.

- **[FLAG]** Dose range values are user-report-only with no controlled study confirmation. The threshold of 100 µg and strong dose of 750–1000 µg have not been verified against published primary sources.

- **[FLAG]** The 3–6 day aftereffect period in the seed data is notably long and has not been confirmed in any published study. Requires editorial review.

### Structural Analogy Dependency
The following sections rely primarily on structural analogy rather than substance-specific data and should be labeled as such in generated article prose:
- All receptor binding affinity data (from NBOH class, not 25C-NBOH specifically)
- All PK data (from 25I-NBOH by structural analogy)
- Cross-tolerance data
- Long-term dependence liability
- Most interaction data (except tramadol mechanism, which is mechanism-confirmed)

### No Community Feedback
No community feedback was submitted for this substance.