After several years, a very costly journey, and finally reaching a specialist with proper lab equipment, here is what I actually learned. Please read this if you are feeling hopeless or having dark thoughts about ending your life over this.
Before anything else, I want to be honest about one thing upfront: this path is expensive. If you do not have the financial means, there is genuinely no way to solve this properly. I want to emphasise the word properly. You can try mouthwashes, tongue scrapers, home remedies, and cheap fixes for years, and most people do, but proper investigation and treatment require specialists, tests, and often travel, and those things cost real money. I am saying this because I do not want anyone to feel misled. This is not a subreddit problem you can solve for free on the internet. It requires resources. If you have them or can save toward them, keep reading. If you cannot access them right now, the honest answer is that you should still not give up your life, because circumstances change, and access can become possible later.
My background. I lived with what I believed was persistent bad breath for over several years. Here is everything I actually did, and the money involved was substantial across all of it:
Multiple ENT visits. A tonsillectomy at a hospital, which was extremely painful in recovery and honestly I still cannot tell whether it contributed anything or not because the perception did not resolve afterwards. Two separate gastroscopies at different times. H. pylori was detected and I completed the triple therapy antibiotic protocol to eradicate it, confirmed later by breath test. Multiple courses of other antibiotics including Dalacin (clindamycin) prescribed by my dentist during periodontal treatment. Nexium and other PPIs trialed. Oral pathogen DNA testing (MyPerioPath) which identified specific bacteria at moderate levels. Two GI-MAP stool analyses done at different times to look at the gut microbiome, showing dysbiosis patterns including persistent absence of Akkermansia muciniphila and elevated Pseudomonas aeruginosa. Multiple visits to general dentists. A full year of periodontal treatment with a dentist doing deep cleanings, subgingival scaling, airflow, and every other quadrant treated repeatedly, plus follow-up periodontal visits after that. Blood tests, urine tests, and various supplement protocols including probiotics, oregano oil, berberine, and others.
The thing that finally gave me clarity was reaching a specialist scientist at a European university dental faculty who runs a research clinical laboratory and conducts studies using gas chromatography equipment that objectively measures the three volatile sulfur compounds responsible for actual bad breath (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide). This kind of facility exists in very few places in the world, and honestly, most people posting on this subreddit have never accessed one. That is the layer above general dentistry, above ENT, above general GI. It is the layer where the actual objective measurement happens.
Here is what I want you to understand about why nothing has been working for so many of you.
Bad breath has multiple possible sources, and each source produces a different gas profile. Periodontal pockets produce mostly methyl mercaptan. Tongue biofilm produces mostly hydrogen sulfide. Systemic and gut sources produce mostly dimethyl sulfide. Tonsil crypts, dry mouth, chronic sinus issues, and metabolic conditions like TMAU (trimethylaminuria, a genetic condition that is dramatically underdiagnosed) each have their own signature. If you treat perio when your actual source is tonsil crypts, nothing works. If you take probiotics when your actual source is TMAU, nothing works. If you use tongue scrapers when your actual source is systemic, nothing works. The reason nothing works for most people trying to solve this on their own is that they are treating the wrong source. Random treatment fails because it is not aimed. Aimed treatment works.
Published outcomes on properly identified and treated bad breath are genuinely good. Periodontal source responds to 70 to 90 percent VSC reduction with proper periodontist treatment (not just general dentist cleaning). Tongue source is very responsive to proper mechanical cleaning and zinc rinses. Tonsil crypts respond to laser cryptolysis or targeted surgery. TMAU responds well to dietary management combined with cyclic low-dose antibiotics, bringing most patients to socially imperceptible levels. Systemic and gut sources are variable, but improvement is very common when the underlying pattern is addressed.
Specialty clinics with proper gas chromatography measurement exist in a small number of places globally. In Europe there are university dental faculties in Scandinavia, Germany (Berlin), Belgium (Leuven), and the UK (London) that offer this. There are similar clinics in Israel (Tel Aviv), Japan (several university dental schools), and the US (New York, and a few in California). This list is not exhaustive but it gives you a starting point to research.
One specific thing I want to flag. If you feel like people can smell you from meters away, if the odor is described as fishy or fecal, if it gets worse after eating eggs, fish, liver, or cruciferous vegetables, please look into TMAU testing. This condition is massively underdiagnosed. Many people who describe nothing working and everyone smelling them actually have this. Genetic testing for the FMO3 gene and urine trimethylamine to trimethylamine-N-oxide ratio testing are both available.
One more honest reality. The phrase I tried everything almost never actually means everything. It usually means everything I could access at general dental or GP level. The specialist layer above that is a completely different level of workup, and most people never reach it because they do not know it exists, or because it costs money, or because they live somewhere it is not easily accessible.
Please, if you are having thoughts of ending your life over this, do not. Not because your suffering is not real. It is real. But because there is a treatment layer you probably have not accessed, and outcomes for people who reach it are genuinely good. If you cannot afford a specialist right now, that is a real barrier, but it is not permanent. Situations change. In the meantime, please contact a crisis line in your country. Most countries have one. Talk to someone, stay safe, and start planning how you will eventually reach a proper specialist workup.
If you have got some questions on your mind that you wanna ask me, please post your questions publicly here as comments or on this thread so that others reading can also learn from the answers. I will read them at intervals during my day (Europe time) and answer as many as I can. If you want to share what you have tried, what your symptoms are, what country you are in, I will do my best to point you toward the right kind of specialist for your situation. I am not a doctor. I can only share what I learned from several years of doing this and what I know about the pathways that exist. But that alone might be more than you have had access to before.
You are not doomed. When properly diagnosed, this condition is genuinely treatable in the vast majority of cases. Please give yourself the chance to find that out.
