Nortilidine: Active Opioid Metabolite of Tilidine with μ‑Opioid Agonism & NMDA Modulation
Overview
Nortilidine is the primary active metabolite of the opioid prodrug tilidine, produced in the liver through demethylation via CYP3A4 and CYP2C19 enzymes. Despite tilidine’s low intrinsic potency, nortilidine exhibits analgesic efficacy comparable to morphine, underpinning tilidine’s therapeutic action.
Chemical & Physical Properties
- IUPAC Name: ethyl (1R,2S)-2-(methylamino)-1-phenylcyclohex-3-ene-1-carboxylate
- Molecular Formula: C₁₆H₂₁NO₂; Molecular Weight: ~259.34 g/mol
- Structural Info: Racemic mixture of two stereoisomers; the (1R,2S)-enantiomer exhibits NMDA receptor antagonism and additional dopaminergic activity.
Pharmacodynamics
- μ‑Opioid Receptor Agonism: Selective agonist at the Mu-opioid receptor with an IC₅₀ around 110 nM—over 100-fold more potent than tilidine itself (11 μM), demonstrating high receptor selectivity.
- NMDA Antagonism: The (1R,2S)-isomer displays NMDA receptor antagonistic activity, unlike many opioids, which may contribute to mild dissociative and analgesic modulation.
- Dopamine Reuptake Inhibition: Reports indicate dopaminergic transporter inhibition, potentially influencing reinforcement effects.
Pharmacokinetics
- Produced in vivo from tilidine via CYP3A4 and CYP2C19 enzymes.
- Nortilidine reaches peak plasma concentration within 25–50 minutes post-tilidine ingestion; elimination half-life is approximately 3–5 hours.
- Eliminated primarily via renal excretion; hepatic impairment may alter efficacy due to reduced formation from the prodrug.
Analgesic Efficacy
Nortilidine is responsible for tilidine’s clinical analgesia, with potency nearly equivalent to morphine despite being generated from a weak parent compound. Both analgesic and sedative effects arise predominantly via μ-opioid receptor activation, reversible by naloxone.
Side Effects & Safety
Common adverse effects reported with tilidine/nortilidine use include nausea, dizziness, sedation, headache, increased sweating and fatigue. Because nortilidine is a potent opioid metabolite, risks include respiratory depression, constipation, tolerance, and dependence similar to other μ‑agonists.
The NMDA antagonism may also contribute to rare excitatory or dissociative side effects, especially at high doses or with repeated exposure.
Harm Reduction & Lab Handling
As a research-grade active opioid metabolite, nortilidine requires careful dosing and handling. Key precautions include:
- Accurate analytical measurement (e.g., mg‑precision scales)
- Awareness of CYP-mediated formation from prodrugs
- Co-administration of naloxone in tilidine formulations may attenuate peripheral effects but does not inhibit central analgesia
- Monitor respiratory and CNS depression in in vivo models
Research & Forensic Applications
Nortilidine is routinely included as a reference standard in forensic toxicology for confirming tilidine use, as well as in mechanistic studies involving μ-opioid signaling and NMDA modulation. Its dual activity makes it a tool for exploring opioid potency, structure-activity relationships, and analgesic vs excitatory risk balance.
Legal & Regulatory Status
While tilidine is medically approved in several countries (often combined with naloxone to deter misuse), nortilidine itself is not marketed and may fall under controlled-analogue laws depending on jurisdiction. Laboratory or research usage must comply with local opioid regulations.
Summary
Nortilidine is the key pharmacologically active metabolite of tilidine, combining potent opioid analgesic activity with NMDA receptor antagonism and dopaminergic involvement. With morphine-equivalent efficacy, rapid onset, and moderate duration, it plays a critical role in tilidine’s effects. As a potent and multifaceted compound, it demands precise handling and clear understanding in both clinical pharmacology and research settings.
Why Buy Nortilidine from RECHEMCO?
★ We have a long trading history in the market so you benefit from our experience.
★ Nortilidine was tested and verified.
★ We accept various payment methods such as Bitcoin, Monero and bank wire.
What you will receive when you buy Nortilidine from RECHEMCO?
• One sealed aluminum foil bag containing highest grade Nortilidine
• powder
• 99% Purity
Christoph (verified owner) –
Got 500mg of Nortili today and researched: no effect at all!!
How is this possible? Is it even an opioid that you sent me?
Rechemco –
Thank you for your feedback.
We are receiving mixed reviews about this new chemical — some researchers are very satisfied, while others, like you, report little to no effect.
It’s also possible that individual tolerance levels play a role in the outcome.
As always, please remember that all RCs are not intended for human or animal consumption. Handle them with maximum care and conduct research responsibly with the proper equipment.
Tim45 (verified owner) –
I gave my plants up to 250mg of Nortilidine, but unfortunately they didnt report any effect. Regarding that its supposed to have an analgesic effeciacy like morphine, their tolerance is neglectable.
Rechemco –
Thank you for sharing your findings.
We’re seeing very mixed reports on this compound — some researchers observe pronounced effects, while others report little to none. That variability makes it unpredictable, so it should be treated as potentially dangerous and handled with extreme caution, regardless of personal results.
Please remember: all products are for research purposes only, not intended for human or animal consumption. Use proper laboratory equipment and follow strict safety protocols. Research carefully and stay safe.
N.M (verified owner) –
I feed my plant with 10mg of this rc and feeling a good effekt and my plants have big tollerance i think its the way you feed your plant
K.A So –
effectively inactive. (non-human) subjects have no tolerance to speak of, even kratom is much better than the batch i received
Rechemco –
Hello and thank you for your review!
We appreciate your feedback and understand your observation. We’ve received mixed reports regarding Nortilidine, and it appears that the route of administration (ROA) plays a crucial role in its effectiveness during research.
If your study focuses on opioid compounds, we offer a range of other options that may provide more consistent or potent results for comparison.
Please remember that all products sold are Research Chemicals, not intended for human or animal consumption. Proper research safety procedures and a precise scale are required.
NB (verified owner) –
Only had 50 mg and researched it all at once but the research was very unsuccesfull
Rechemco –
Hello and thank you for your review!
We appreciate your feedback. We’ve noticed that research outcomes with Nortilidine can vary, and the route of administration (ROA) seems to have a significant impact on effectiveness.
If you’re exploring this class of compounds, you might consider comparing it with other opioids available in our catalog, which may offer more consistent or pronounced results depending on your research setup.
Please remember that all products sold are Research Chemicals, not intended for human or animal consumption. Proper research safety procedures and a precise scale are required.
Sebastian Kreuzer (verified owner) –
After being confronted with this compound, my plant did not change in any way at all, as much as I tried to confront it, no change.
Rechemco –
Hello and thank you for your review!
We appreciate your feedback and understand your observation. We’ve received mixed results from researchers working with Nortilidine, and it seems that the route of administration (ROA) plays a key role in achieving measurable outcomes.
If your research aims to study opioid-like compounds, you may want to explore some of the other available options in this category, which could provide more consistent or notable effects under similar conditions.
Please remember that all products sold are Research Chemicals, not intended for human or animal consumption. Proper research safety procedures and a precise scale are required.
Luigi –
Hi, I reed the reviews about Nortilidin and I can explain why it not work about the oral route:
1. First-pass effect (hepatic metabolism)
When nortilidine is absorbed through the intestine, it is transported directly to the liver via the portal vein.
In the liver, it is rapidly oxidized to bisnortilidine (which is less active) and conjugated (phase II reaction), meaning it becomes inactivated.
As a result, only a very small amount of the drug reaches the systemic circulation.
2. Low oral bioavailability
The data are limited (since nortilidine has never been clinically tested as a medication), but based on its chemical properties — being relatively polar and easily oxidized — it is assumed that its oral bioavailability would be extremely low, probably below 10%.
3. Short half-life
Nortilidine has a short half-life (around 1 hour or less) because it is rapidly metabolized further.
This additionally means that it can hardly maintain a stable plasma concentration.
I don’t want to encourage anyone to use other or dangerous routes of administration! Now you know why it doesn’t work — it has too low oral bioavailability.
Stay safe! Make your own research and Safer Use!
Luigi –
And also nasally it can’t work.
Paketservice Alex Appenzeller (verified owner) –
NorTilidine appears to be pleasant and beneficial, judging by the behavior of the test subject.
A pronounced warmth, physical well-being, and (logically) pain-relieving effects were observed.
The test subject seems to behave similarly to those in trials with O-DSMT, but without the strong euphoria and energy boost;
it seems to be more calm and relaxed. Crucially, however, it must be presented to the test subject in the right location; then it is highly recommended for researchers’ tests!
But this correct spot, somewhere down at the base of the plant, first needs to be found. In any case, it’s not the normal, old-known linguistic route.
Lygelll (verified owner) –
Only bought the minimal amount and I slightly regret not purchasing more ! This stuff is relatively good for hypothetically untolerant users. A freshness was rapidly felt inside the whole mouth then effects progressed to a nice chill vibe that completely surprised the fictional experimental subject