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How to Use Dextromethorphan for POTS, anxiety, depression, autoimmunity, and Chronic Pain, revised

What is dextromethorphan?

Dextromethorphan is an NDMA antagonist available over the counter as a cough suppressant in products such as Robitussin gels (many other products contain various harmful ingredients and should be avoided by those with high blood pressure). It has been studied as a treatment for neuropathic pain in Fibromyalgia, Multiple Sclerosis, and Traumatic Brain Injury. Here are some studies that show effectiveness.

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An extension of hypotheses regarding rapid-acting, treatment-refractory, and conventional antidepressant activity ofdextromethorphan and dextrorphan.

What are the Benefits and Risks?

I have found that a dose of 150 mgs produces an antidepressant and antipain effect with onset after 2 hours and lasting several days superior to traditional opiates, antidepressants, and anxiolytics.

Dextromethorphan may also ameliorate POTS, anxiety, and depression for a few days at a 150mg dose, for some. The highest dose used in studies has been around 400mgs. Since it also induces rapid recovery from depression, it's most likely to work when POTS has a mostly neurological cause, especially affecting glutamate, serotonin, norepinephrine or their transporters.

Dextromethorphan also has antiinflammatory properties which can reduce inflammatory reactions in the intestines and on the skin.

Dextromethorphan is not approved for over-the-counter use at that dose and at doses higher than 90mgs and can have potentially life threatening drug interactions or produce dissociative hallucinations similar to those seen in PCP and ketamine abuse.

Here are the most potentially dangerous possible side effects.

  1. Serotonin Syndrome. This may occur due to interactions with other psychoactive medications (antidepressants and opiates), or due to poor metabolism.

2. Delirium, psychosis. This may occur due to abuse or accidental overdose.

3. Altered behavior. At high doses, abusers may become unable to feel fear or pain and exhibit erratic or violent behavior similar to PCP intoxication.

4. Reactions to other ingredients. Some abusers use preparations containing other ingredients such as phenylephrine and acetaminophen which can cause dangerous high blood pressure or liver failure at high doses.

I estimate that the therapeutic dose range is from 90 to 300 mgs per day.

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Recreational users abuse doses in the range of 300 to 900 mgs, which are dangerous and will causes psychosis, movement problems, and insensitivity to pain similar to the effects of PCP. Some of their experiences and other information on dextromethorphan can be found here

To put things in perspective, equally potent pain relieving doses of oxycontin, tramadol, methadone, and most pain meds or antidepressants are far more dangerous than an equivalent dose of dextromethorphan. However, dextromethorphan is an opioid derivative and SNRI and can have any of the side effects of opioids or antidepressants when used at higher doses.

Dextromethorphan was created as a non-addictive alternative to codeine. As a non-addictive opioid, it would be the standard for pain treatment if in fact the industry thrived off of non-addictive medications, which is not the case, which is why dextromethorphan costs 5 dollars at the grocery store and a drug like oxycontin, also an opioid derivative, costs hundreds of dollars by prescription only. But we don't personally have to be fooled by a corrupt system.

How Can I Use Dextromethorphan therapeutically?

Step 1. Get instructions from your doctor.

Discuss with your doctor that you would like to try dextromethorphan as used experimentally in studies for chronic pain.

Step 2. Find the right product.

Choose products with only dextromethorphan listed as the active ingredient. Robitussin gels is an example.

Step 3. Find the right dose.

This is the most critical and controversial step. You may take up to 90 mgs per day for cough suppression without a doctor’s advice but doses above that legally require a prescription. I estimate a therapeutic range from 90 to 300 mgs for chronic pain with most people requiring about 150 mgs.

Step 4. Eliminate drug interactions.

Dextromethorphan generally has the same side effects as SSRI antidepressants. The links below show the drug interactions for prescription dextromethorphan.


DXM syrup

Step 5. Discuss a trial of dextromethorphan with your doctor.

If your doctor will approve it, a four day trial of 90, 120, 150 mgs will demonstrate if the medication will be effective for your particular chronic pain issue. You might try 90 the first day and note any side effects, then 120 the next day, and finally 150 on day 3. On day three and four, you will experience the full effects and can decide based on that whether the medication may be effective for you.

As a disclaimer, I am a certified psychotherapist. I am not a doctor and cannot make medication recommendations. I have chronic pain from Ehlers-Danlos Syndrome, fibromyalgia, and POTS and I am sharing my research into therapies that have helped. Get better sooner :)



Addendum, How to block side effects 7/13/2014

NMDA antagonists like dextromethorphan and ketamine are shown to act as rapid-acting antidepressants, immuno-modulators, and pain medications. Their use is limited due to the risk of serotonin syndrome or recreational hallucinations in users who do not want such effects. Recreational effects appear about 2 hours after a dose of 300 mgs or more of dextromethorphan in most users.

I have discovered these side effects can blocked by stabilizing with supplemental lithium orotate containing 1mg to 10 mgs of lithium (1/4 pill to 2 five mg pills) for at least 3 days before dosing with dextromethorphan. The lithium prevents the surge of serotonin neurotransmission which causes the temporary delirium and disorientation recreational users seek. The modulation of serotonin in turn prevents a surge of prolactin, greatly reducing sexual side effects. Many people may get results taking just 1/4 of a pill to 1 pill per day to maintain the effect. The drawback is some people think the serotonin and slight recreational effects are key to antidepressant action and would rather use lithium only to take a break from side effects.

Some people are poor metabolizers so a doctor's monitoring is crucial. Also, though 10 mgs or less of lithium orotate is unlikely to build up significantly in one's system, a doctor can measure your lithium level to be sure.

Several dosing schedules may be discussed with your doctor. The patient should take lithium orotate daily as tolerated as a supplement, but DXM should be taken every two to three days, or as long as a week depending on response. It should not be taken daily. It should be taken in the morning as it can affect sleep. Blood pressure should be monitored to assure it does not cause hypertension.


For an adult, normal metabolizer, 90 to 150 mgs of dextromethorphan.. For those who are antidepressant naieve, only one 90 mg dose may be needed. Repeat every 2 to 3 days, or once per week as needed.

Lithium orotate: Stabilize on 1 mg to 10 mg to per day to block dxm side effects and enhance antidepressant effect. Lithium orotate supplements generally come in pills containing 5 mgs of lithium. The recommended supplemental dose is far less than use for bipolar patients, who take 80 to 100 mgs of lithium from lithium carbonate.

For autoimmune conditions, two doses of dxm may be needed. I have used DXM to treat my Hidradenitis suppurativa with success but only with a two dose regimen.

Again, none of this should be attempted without a doctor's monitoring but if you are ill and the doctor is treating you with far more dangerous medications such as oxycontin and benzodiazepines, this may be an avenue to explore.


tarad6262 on June 03, 2017:

Help: this article is a bit confusing. So to go with doses over 90 mg. you can't use it from the otc? The doctor actually can prescribe it and any pharmacy will fill it? Also does the otc product contain only dxm? nothing else correct?

BPainFreeTherapy (author) from USA on August 05, 2015:

i have personally used it with phenibut. I would dose them as far apart as possible at first to avoid interactions. Be sure to do some research on it and check erowid to see if anyone has tried them together.

jason on July 07, 2015:


I know its kind of an old thread but I wanted to know if it's ok to use it with phenibut?


Pharmg23 on August 23, 2012:

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Belinda on June 06, 2012:

Thank you

Really interesting

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