Conclusion: Overall 26 RCTs involving 848 dogs were included. Tramadol administration probably results in a lower need for rescue analgesia versus no treatment or placebo [moderate CoE; relative risk (RR): 0.47; 95% confidence interval (CI): 0.26-0.85; I2 = 0%], and may result in a lower need for rescue analgesia versus buprenorphine (low CoE; RR: 0.50; 95% CI: 0.20-1.24), codeine (low CoE; RR: 0.75; 95% CI: 0.16-3.41) and nalbuphine (low CoE; RR: 0.05; 95% CI: 0.00-0.72). However, tramadol administration may result in an increased requirement for rescue analgesia versus methadone (low CoE; RR: 3.45; 95%
PubMed 33745825 ↗Codeine
Based on 4 first-hand reports and 134 meta-analyses & systematic reviews in the medical literature. Ranked #2104 of 4,149 overall.
Of reports that state an outcome, 50% are positive.
What Codeine does, according to users
Of the people who reported each effect, the share who said it got better.
What the research says
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: There is moderate-certainty evidence that oromucosal nabiximols and THC are ineffective in relieving moderate-to-severe opioid-refractory cancer pain. There is low-certainty evidence that nabilone is ineffective in reducing pain associated with (radio-) chemotherapy in people with head and neck cancer and non-small cell lung cancer. There is low-certainty evidence that a single dose of synthetic THC analogues is not superior to a single low-dose morphine equivalent in reducing moderate-to-severe cancer pain. There is low-certainty evidence that CBD does not add value to specialist palliative c
PubMed 37283486 ↗Conclusion: Based on low- and very low-certainty evidence, most interventions were classified as no more harmful than placebo for most adverse effects. Based on moderate- and high-certainty evidence, NSAIDs with or without acetaminophen result in better pain-related outcomes than opioids with or without acetaminophen (except acetaminophen 650 mg plus oxycodone 10 mg) or placebo.
PubMed 36631957 ↗Conclusion: The amount and quality of evidence around the use of opioids for treating cancer pain is disappointingly low, although the evidence we have indicates that around 19 out of 20 people with moderate or severe pain who are given opioids and can tolerate them should have that pain reduced to mild or no pain within 14 days. This accords with the clinical experience in treating many people with cancer pain, but overstates to some extent the effectiveness found for the WHO pain ladder. Most people will experience adverse events, and help may be needed to manage the more common undesirable adverse effe
PubMed 28683172 ↗Dosage people report
As stated by users — not a recommendation. Follow the label or your doctor.
Reported side effects
How often each side effect came up across all reports.
What users say
First-hand experiences, quoted verbatim. We show one positive and one negative where both exist.
“I've had developed a permanent tolerance to codeine's euphoriant effects, but during my 20 day BPC-157 500mcg/day cycle I've tried codeine once...It felt like the first times.”
“This is now my second time trying codeine and I don't like it. Maybe I'm not having enough to feel the drowsy side of it, but both times, it's made me feel uncomfortable and restless. 4/10, would not try again.”
Top discussions (4)
- BPC-157 might permanently increase Amphetamine tolerance; In rats, a single injection of BPC-157 reduced the stimulant effects of an Amphetamine dose given 46 days later ↗
- The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. ↗
- Pseudoephedrine as an alternative to Caffeine ↗
- Sedative ↗
More medications
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 3, 2026. How we rate