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Ultimate 25I-NBOMe Guide: Effects, Common Uses, Safety

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25I-NBOMe, also known as “N-bomb” and “25I,” is a potent synthetic psychedelic. German chemist Ralf Heim first synthesized it in 2003 at the Free University in Berlin. A few years later, a team led by Dr. David Nichols picked up the 25I-NBOMe research at Purdue University. They developed a radio-labeled form of the drug to map the serotonin receptor system using Positron Emission Tomography (PET) imaging. Once it escaped the laboratory, it made its debut on the online research chemical market in 2010. Compared to LSD, 25-NBOMe has a similar effect profile and route of administration but a significantly lower safety profile. In response to a series of deaths and hospitalizations attributed to the drug, it was made illegal in 2013 and placed on Schedule I three years later.

What is NBOMe?

NBOMe is a class of novel phenethylamine psychedelics that all act as potent partial agonists of serotonin 5-HT2A receptors. The “NB” in the name stands for N-benzyl, while the “OMe” stands for methoxy. 

The NBOMe compounds are N-benzylmethoxy derivatives of the 2C family of compounds. The 2C family is a class of phenethylamines produced by systematically modifying the mescaline molecule. Dr. Alexander Shulgin synthesized these compounds in the 1970s and 1980s. He published his findings in his book, PIHKAL (Phenethylamines I Have Known and Loved). The N-benzylmethoxy structural addition to the phenethylamine backbone results in a significant increase in potency, up to 16 times that of the corresponding 2C compound.

The NBOMe series are considered designer drugs because they are made in the laboratory, rather than produced from natural precursors (such as LSD). However, similar to LSD, they are active at sub-milligram doses and produce similar hallucinogenic effects at commonly used doses. They had no history of human use until 2010, when online research chemical vendors began to sell them. Researchers have described up to nine different variants of the NBOMe class of compounds. Three of them, 25I-NBOMe, 25B-NBOMe, and 25C-NBOMe, have been placed in Schedule I.


Also known as 2C-I-NBOMe, 25I-NBOMe is an N-benzyl derivative of the phenethylamine psychedelic 2C-I. The addition of the methoxybenzyl group to 2C-I increases the drug’s affinity for the 5-HT2A receptor by up to 16 times. 25I-NBOMe was the first and is the most popular of the NBOMe class of compounds. It is typically sold on blotters, similar to LSD, but can also be found in powder and liquid forms.


25C-NBOMe, or 2C-C-NBOMe, is a derivative of the phenethylamine 2C-C. It is an active hallucinogen at doses as small as 200–300 micrograms (ug), while a light dose of 2C-C is approximately 15 mg. It comes most commonly as tabs that range from 300–350 ug, but also as a liquid and powder. At least one death has been associated with 25C-NBOMe since its introduction to the research chemical market in 2010.


25B-NBOMe, also known as 2C-B-NBOMe, is a derivative of the phenethylamine psychedelic 2C-B. As with 25I-NBOMe, researchers have used 25B-NBOMe to study the serotonergic system as a radio-labeled tracer for PET imaging. 25-B-NBOMe is most commonly found in tabs that range from 300-350 ug, but also in pure powder and liquid form. The recreational use of 25B-NBOMe has led to several nonfatal intoxications and at least 2 deaths since 2010.

Common Ways to Use 25I-NBOMe

As with LSD, makers typically drop 25I-NBOMe liquid on blotter paper. The powder can also dissolve in water. Snorting 25I-NBOMe produces a more intense and short-lasting psychedelic experience. However, the possibility of both dosing errors and toxic reactions strongly discourages this method. There are several reports of hospitalizations and deaths attributable to intranasal use.


Due to its extensive first-pass metabolism, 25I-NBOMe is inactive orally and must be taken sublingually. In the sublingual method, users place the tab in the mouth and hold it there for 15–30 minutes; the drug then absorbs through the mucus membranes. 25I-NBOMe has a distinctly chemical taste commonly described as metallic or bitter. It also frequently numbs the tongue, which can persist for up to an hour. In contrast, LSD does not numb the mouth and is generally tasteless.

History & Traditional Uses

Heim first synthesized and investigated NBOMe compounds as part of his PhD work. He was searching for pharmacological tools to study serotonin 5-HT2A receptors in the brain. By the next decade, NBOMe compounds were being used to map the distribution of 5-HT2A receptors using PET imaging. In 2008, Dr. David Nichols and his research team continued with their research at Purdue University and were the first to synthesize 25I-NBOMe in America. The team was investigating the pharmacology of NBOMe compounds and the mechanisms of 5-HT2A receptor activation. In a short 2016 documentary, Dr. Nichols commented on his reasons for studying the compounds, stating:

“If we understand what it does, it might be possible to use that same strategy on therapeutic drugs, and make them for example, much more potent or much more selective.” 

By 2010, online research chemical vendors began distributing NBOMe compounds, and chief among them was 25I-NBOMe. A few years later, its recreational use as an LSD alternative eventually led to reports of toxicity and fatalities. 25I-NBOMe was emergency scheduled in response, and permanently added to schedule I in 2016.

Commonly Reported Effects of 25i-NBOMe

A threshold dose of 25I-NBOMe is 50–250 micrograms; a light dose is 200–600 micrograms; and a common dose is 500–800 micrograms. Strong doses, anywhere from 700–1500 micrograms, increase the probability of serious adverse effects, including nonfatal intoxications and death.

After taking 25I-NBOMe sublingually, it starts to produce an effect as soon as 15 minutes. The experience peaks within two hours, and the comedown lasts 1–4 hours. The total trip lasts approximately 6–10 hours, and aftereffects have been reported to last as long as 1–7 days. 


The physiological effects of 25I-NBOMe generally include: 

  • Physical stimulation
  • Body load 
  • Nausea (normally as it is taking effect)
  • Insomnia
  • Pupil dilation
  • Increased heart rate
  • Increased blood pressure
  • Increased body temperature
  • Muscle spasms and tension
  • Numbness/coldness in extremities
  • Increased libido


Users describe the psychological effects of 25I-NBOMe as similar to those of LSD. However, it generally produces a heavier visual trip at commonly used doses. The psychological effects may include:

  • Closed and Open Eye Visuals
  • Auditory hallucinations
  • Mental stimulation
  • Mood lift
  • Euphoria
  • Enhanced analytical/creative/conceptual thinking
  • Increased music appreciation
  • Enhanced empathy and sociability
  • Perceived time dilation
  • Synesthesia
  • Fits of laughter (normally during the come-up)
  • Dissolution of ego
  • Spiritual ideation and grand insights

One user described his experience taking one blotter tab of 25I-NBOMe with a friend in 2011:

“25I is probably the most stereotypical/recreational psychedelic drug I have ever used, and I’ve used quite a few psychedelics. 25I makes me feel good, I have insane visuals, and it doesn’t disrupt my language abilities (that much). It is almost nothing like 2C-I. Just because it has a 16x greater potency for the 5-HT2a receptor DOES NOT mean that this compound is just a 16x more potent version of 2C-I. In my opinion, 25I was more comparable to LSD/shrooms, than any phenethylamine I have used. However, despite its high recreational value, I do not consider this drug profound on the level of shrooms, Ayahuasca, or salvia.”

Adverse Effects

25I-NBOMe has caused significantly more dangerous responses and deaths than any other serotonergic psychedelic. The probability of adverse effects increases, dependent on dose. These can include:

  • Racing thoughts and thought loops
  • Scrambled communication
  • Confusion
  • Serotonin syndrome
  • Muscle aches
  • Agitation
  • Panic and anxiety
  • Paranoia
  • Delirium
  • Higher seizure risk
  • Vasoconstriction
  • Acute kidney injury

25I-NBOMe vs Acid

LSD is a semisynthetic ergoline psychedelic first synthesized by Albert Hofmann in 1938. It has been used in recreational and medical contexts for more than half a century, and its long-term effects, safety, and toxicity are well-known. On the other hand, 25I-NBOMe is a synthetic phenethylamine psychedelic that has been used recreationally for only a decade (as of this writing). No studies have evaluated its long-term safety and toxicity in humans, and a lot of the data comes from case studies of intoxications and anecdotal reports on forums. 

While it’s nearly impossible to overdose on LSD (a 75kg person would have to take roughly 12,000 doses to overdose), 25I-NBOMe has resulted in numerous overdoses at doses at or above roughly 1.5 mg. Its sensitive dose-response profile, coupled with its potent, unpredictable effects, makes 25I-NBOMe much less safe in comparison to LSD. Another distinguishing characteristic is that LSD is generally tasteless, apart from the ink on the blotter. In contrast, 25I-NBOMe has a bitter or metallic taste, and commonly numbs the tongue after dosing.

As for similarities, LSD and 25I-NBOMe are both potent psychedelics that act on serotonin 5-HT2A receptors. They are both usually dosed on blotters at sub-milligram dosages. 25I-NBOMe has been sold and used under the guise of LSD due to this similarity. The consequences of this deception can range from a different, possibly unpleasant trip at best to an overdose at worst. Subjectively speaking, LSD and 25I-NBOMe have similar effects, but 25I-NBOMe generally produces a heavier visual trip and a less clear headspace. Many individuals report more negative side effects on 25I-NBOMe, including an unpleasant body load. 

Safety Precautions

Because 25I-NBOMe is a novel research chemical, its safety, toxicity, and long-term health effects are largely unknown. By 2013, there were 19 deaths attributed to NBOME, and this number is even higher today. People with preexisting mental health or heart conditions should not use 25I-NBOMe. The compound can produce vasoconstriction, which may put stress on the cardiovascular system and, in extreme cases, result in cardiac arrest. 


In addition, 25I-NBOMe can exacerbate preexisting mental health conditions or trigger latent mental illness in susceptible individuals. Even in non-predisposed individuals, difficult experiences strongly tied to set and setting can lead to lasting anxiety and PTSD. The drug has also produced higher rates of Hallucinogen Persisting Perception Disorder (HPPD) and lasting dissociation, compared to classical psychedelics. 

If you are currently taking any medication that raises serotonin levels, such as SSRIs, do not take 25I-NBOMe. Taking serotonergic drugs with 25I-NBOMe can result in serotonin syndrome, a potentially fatal condition characterized by agitation, confusion, delirium, abnormal heart rate, sweating, and tremors.

Avoid taking 25I-NBOMe with stimulants, such as amphetamines and cocaine. This combination can put further stress on the cardiovascular system and lower the seizure threshold. Avoid risky combination to avoid is tramadol with 25I-NBOMe, as both lower the seizure threshold.

Dosing Safely

Apart from individual reactions and contraindications, dosing errors can also cause overdoses. It can be difficult to dose 25I-NBOMe without an accurate and highly sensitive scale. Further complications arise from inaccurate or irresponsible blotter dosages. Because of this, excessively strong doses have caused subsequent fatalities. It’s always best to start with a light dose to gauge one’s individual reaction, then slowly titrate up, if at all. As a general rule of thumb, mitigate adverse effects by never dosing more than 1 mg.

Lastly, cautious users who want to ensure the blotter they are taking is LSD and not 25I-NBOMe should get and use a testing kit. The Ehrlich reagent turns pink-purple in the presence of LSD, while 25I-NBOMe will lead to no color change.


How Long Does a 25I-NBOMe Trip Last?

When used sublingually, 25I-NBOMe typically lasts about 6–10 hours with a comedown period of 1–4 hours.

How Long Does 25I-NBOMe Stay in Your System?

The pharmacokinetics of 25I-NBOMe haven’t been studied in depth, so it’s unclear how long it stays in the body. With that said, standard and extended drug tests do not check for 25I-NBOMe. 

Is 25I-NBOMe Dangerous?

Yes, it can be. Compared to the classic psychedelics, 25I-NBOMe has a low margin of safety due to its unique potency and toxicity. Its potential for harm escalates significantly at doses above 1 mg. In addition to the potential for overdose, 25I-NBOMe is associated with a higher rate of negative aftereffects, including HPPD, dissociation, and other mental health issues. Sold under the guise of LSD, 25I-NBOMe can lead to users taking too much and possibly overdosing. Snorting 25I-NBOMe is also dangerous, as this method has been linked to several nonfatal overdoses.

Is 25i-NBOMe Addictive?

There is little to no data concerning the abuse potential of 25-NBOMe. Similar to other serotonergic psychedelics, it’s not believed to be addictive and has a low potential for abuse. 

Can You Die from 25I-NBOMe?

Yes. Around the world, dozens of people have died from 25I-NBOMe. Dosage errors, improper set and setting, idiosyncratic reactions, and risky combinations can all contribute to a fatal overdose.

25-NBOMe is not legal. It was permanently added to Schedule I in October of 2016. 

Disclaimer: 25I-NBOMe is potentially categorized as an illegal drug. Reality Sandwich is not encouraging the use of this drug where it is prohibited. However, we believe that providing information is imperative for the safety of those who choose to explore this substance. This guide is intended to give educational content and should in no way be viewed as medical recommendations.

RS Contributing Author: Dylan Beard 

Dylan Beard is a freelance science writer and editor based in the beautiful Pacific Northwest. After finishing his physics degree and dabbling in neuroscience research at UC Santa Barbara in 2017, he returned to his first love: writing. As a long-term fan of the human brain, he loves exploring the latest research on psychedelics, nootropics, psychology, consciousness, meditation, and more. When not writing, you can probably find him on hiking trails around Oregon and Washington or listening to podcasts. Feel free to follow him on Insta @dylancb88.


  • Reality Sandwich

    Life is Psychedelic. Reality Sandwich serves you the most up to date information on psychedelic science, art, culture, news and substances. Knowledge is power, have a bite!

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