What Are Mycotoxins?

Mycotoxins are highly toxic chemical compounds produced by certain species of mould.
Invisible to the eye and scentless, they can be inhaled, ingested, or absorbed through the skin. Mycotoxins are the underlying cause of mould illness, affecting multiple body systems.
Understanding what they are—and how to reduce exposure - is essential for effective mould remediation, home safety, and long-term recovery from mould-related illness.
About the Author
Lia de Lancey BSc MSc DipNT MNBP
Trained with MastCell360 & Dr Jill Crista, specialising in mould illness and mineral nutritional balancing.
Learn more on our About page.
What Exactly Are Mycotoxins?
Key takeaway:
Mycotoxins are chemicals that moulds release as a defense mechanism to compete with other microorganisms in their environment.
Mycotoxins are microscopic, fat-soluble toxins produced by mould. They can be inhaled, ingested, or absorbed through the skin and are found in air, dust, and on surfaces—even when no visible mould is present. Because of their extreme toxicity, some have been studied as biological weapons1. Mycotoxins are the cause of mould illness and a major cause of chronic health problems.
They are incredibly small, measuring about 0.1 micron, which means they can pass easily through building materials and remain in the air or dust even after visible mould has been removed. You can’t see or smell them, yet they can linger long after remediation if not properly addressed.
Because mycotoxins are lipophilic (fat-loving), they can pass through skin, cell membranes, and even the blood-brain barrier2. This allows them to accumulate in fatty tissues and organs, contributing to persistent symptoms long after initial exposure.
Because they’re so small and pervasive, even hidden mould can make you sick—such as mould behind walls, under floors, or inside HVAC systems.
Common types of mycotoxins and where they come from
Key takeaway:
Different mould species produce specific types of mycotoxins—each with unique health effects3, 4.
| Mycotoxin | Produced by | Notes / Key Facts |
|---|---|---|
| Aflatoxin | Aspergillus flavus, A. parasiticus | Potent liver toxin and carcinogen5 |
| Chaetoglobosin A, C | Chaetomium globosum | Neurotoxic and immune-suppressive6 |
| Gliotoxin | Aspergillus fumigatus | Disrupts immune function; linked to chronic respiratory issues7 |
| Ochratoxin A | A. ochraceus, A. niger, Penicillium verrucosum, P. nordicum, P. chrysogenum | Damages kidneys and nervous system; immunosuppressive8, 9 |
| Sterigmatocystin | A. versicolor | Precursor to aflatoxin; highly carcinogenic10 |
| Trichothecenes (Roridin E, Verrucarin A) | Stachybotrys chartarum, Trichoderma viridae, Fusarium spp, Cephalosporium | Toxic to the circulatory system, endocrine disruptors11, 12 |
| Enniatin B | Fusarium spp | Damages cell membranes, mitochondri, neurotoxic13 |
| Zearalenone | Fusarium spp | Hormone-disrupting; mimics estrogen and affects fertility14 |
| Citrinin | Penicillium spp, Aspergillus spp, Monascus spp | Kidney toxin; often found with ochratoxin A5 |
Health Effects of Mycotoxins
Key takeaway:
Mycotoxins can affect almost every system in the body—especially the brain, immune system, and detox organs.
Common symptoms include16:
- Fatigue and weakness
- Brain fog, poor memory, or dizziness
- Chronic sinus congestion or cough
- Headaches and migraines
- Skin rashes, eczema, and itching
- Digestive problems and food sensitivities
- Hormonal imbalance and fertility issues
- Anxiety, depression, or mood changes
Because mycotoxins are lipophilic, they tend to lodge in fatty tissues (like the brain, liver, and nerves), which can make recovery slow if detox pathways are impaired.
Why Understanding Mycotoxins Matters
Key takeaway:
Mycotoxins are the root cause of mould illness – and knowing this helps inform mould protocols and remediation to prevent re-exposure.
Recognising that mould illness is driven by mycotoxins changes how we approach both mould illness protocols and remediation.
Effective Protocols
Once we understand that mould illness is driven by mycotoxin accumulation rather than ongoing allergen exposure, it becomes clear that standard symptomatic treatments – antihistamines, antidepressants, or pain relief – address the symptoms but not the cause.
Knowing this, we can identify the best ways to support the body’s efforts to eliminate mycotoxins, which is why specialist guidance matters. Based on clinical training with Dr Jill Crista and MastCell360, this forms the foundation of the approach used at Mother of the Woods.
Effective Remediation
When it comes to remediation, simply removing visible mould isn’t enough – you must also address the mycotoxins left behind.
Unfortunately, many mould cleaning services focus only on killing spores but ignore the residual toxins coating your home and possessions. These toxins remain even after mould is dead. Look for a remediator that offers ozone treatment, as this will not only kill mould spores but should also destroy mycotoxins. Ozone treatment must be carried out by a professional – the space must be fully vacated during treatment as ozone is exremely harmful to breathe.
If you move house rather than remediating, you can bring mycotoxins with you on clothes, books, and furniture – so understanding their nature is key to full recovery. The extent of cleaning required depends on the severity of your illness and the degree of contamination.
Here are a few tips:
- If you have to enter a mouldy space, wear a full PPE suit and use the best quality mask you can find – ask your remediator where to source one in your area. You need a mask that filters out as many 0.1 micron particles as possible.
- If you haven’t used ozone, you will need to clean your possessions. Antimicrobial products are unnecessary, simply wiping your possessions is good enough in many cases, but the cloth must be thrown away afterwards, so I suggest a low tox, biodegradable brand of wipes like Water Wipes, so you don’t keep reusing the same cloth.
- Wet mop and thoroughly dry floors.
- Curtains and clothes can be washed with borax (½ cup of borax in the washing machine before putting your clothes in) or potentially treated with ozone (depending on the fabric and length of exposure).
- Carpets, duvets, cushions, pillows, soft furnishings, and soft toys are best disposed of. Get the carpet done by a professional to avoid getting re-exposed.
- Get dust mite covers for your mattresses and never open them again.
- Place anything for disposal into heavy duty bin bans, seal, and immediately remove from the house.
- If you are short of time to clean your possessions, consider renting a storage space for a few months while you slowly work through it. When packing up your possessions, place them into good quality plastic containers with well fitting lids. Ensure that you are taking measures in the storage space to avoid damp and mould (eg silica). When you bring your possessions back home, clean them before bringing them into the house.
Taking the Next Step
Key takeaway:
If you are concerned you may be experiencing symptoms of mould illness, there is support is available in the UK & Ireland.
It’s completely understandable to feel worried if you’re experiencing any of the symptoms mentioned above. Mould illness is complex, but there are practical steps you can take to identify exposure, support your body, and begin recovery.
If you want to learn more, you can download our free ebook Is Mould Making You Unwell?, or contact us directly and we’ll help you get the help you need.
References
- Anderson PD. Bioterrorism: toxins as weapons. J Pharm Pract. 2012 Apr;25(2):121-9. doi: 10.1177/0897190012442351. PMID: 22523138.
- Behrens M, Hüwel S, Galla HJ, Humpf HU. Blood-Brain Barrier Effects of the Fusarium Mycotoxins Deoxynivalenol, 3 Acetyldeoxynivalenol, and Moniliformin and Their Transfer to the Brain. PLoS One. 2015 Nov 23;10(11):e0143640. doi: 10.1371/journal.pone.0143640. PMID: 26600019
- Hope J. A review of the mechanism of injury and treatment approaches for illness resulting from exposure to water-damaged buildings, mold, and mycotoxins. Scientific World Journal. 2013 Apr 18;2013:767482. doi: 10.1155/2013/767482. PMID: 23710148
- Peraica M, Radić B, Lucić A, Pavlović M. Toxic effects of mycotoxins in humans. Bull World Health Organ. 1999;77(9):754-66. PMID: 10534900
- Benkerroum N. Chronic and Acute Toxicities of Aflatoxins: Mechanisms of Action. Int J Environ Res Public Health. 2020 Jan 8;17(2):423. doi: 10.3390/ijerph17020423. PMID: 31936320
- Duan F, Qin C, Sang Z, Wei X, Ruan H. Lignans and [11]-chaetoglobosins from Pseudeurotium bakeri and their immunosuppressive activity. Org Biomol Chem. 2024 Mar 13;22(11):2271-2278. doi: 10.1039/d3ob02109b. PMID: 38391281.
- Günther K, Nischang V, Cseresnyés Z, Krüger T, Sheta D, Abboud Z, Heinekamp T, Werner M, Kniemeyer O, Beilhack A, Figge MT, Brakhage AA, Werz O, Jordan PM. Aspergillus fumigatus-derived gliotoxin impacts innate immune cell activation through modulating lipid mediator production in macrophages. Immunology. 2024 Dec;173(4):748-767. doi: 10.1111/imm.13857. Epub 2024 Sep 13. PMID: 39268960.
- Malir F, Ostry V, Pfohl-Leszkowicz A, Malir J, Toman J. Ochratoxin A: 50 Years of Research. Toxins (Basel). 2016 Jul 4;8(7):191. doi: 10.3390/toxins8070191. PMID: 27384585
- Sharma RP. Immunotoxicity of mycotoxins. J Dairy Sci. 1993 Mar;76(3):892-7. doi: 10.3168/jds.S0022-0302(93)77415-9. PMID: 8463496.
- Wang JS, Groopman JD. DNA damage by mycotoxins. Mutat Res. 1999 Mar 8;424(1-2):167-81. doi: 10.1016/s0027-5107(99)00017-2. PMID: 10064859.
- Parent-Massin D. Haematotoxicity of trichothecenes. Toxicol Lett. 2004 Oct 10;153(1):75-81. doi: 10.1016/j.toxlet.2004.04.024. PMID: 15342083.
- Ndossi DG, Frizzell C, Tremoen NH, Fæste CK, Verhaegen S, Dahl E, Eriksen GS, Sørlie M, Connolly L, Ropstad E. An in vitro investigation of endocrine disrupting effects of trichothecenes deoxynivalenol (DON), T-2 and HT-2 toxins. Toxicol Lett. 2012 Nov 15;214(3):268-78. doi: 10.1016/j.toxlet.2012.09.005. Epub 2012 Sep 12. PMID: 22982764.
- Krug I, Behrens M, Esselen M, Humpf HU. Transport of enniatin B and enniatin B1 across the blood-brain barrier and hints for neurotoxic effects in cerebral cells. PLoS One. 2018 May 16;13(5):e0197406. doi: 10.1371/journal.pone.0197406. PMID: 29768483
- Hueza IM, Raspantini PC, Raspantini LE, Latorre AO, Górniak SL. Zearalenone, an estrogenic mycotoxin, is an immunotoxic compound. Toxins (Basel). 2014 Mar 13;6(3):1080-95. doi: 10.3390/toxins6031080. PMID: 24632555
- de Oliveira Filho JWG, Islam MT, Ali ES, Uddin SJ, Santos JVO, de Alencar MVOB, Júnior ALG, Paz MFCJ, de Brito MDRM, E Sousa JMC, Shaw S, de Medeiros MDGF, Dantas SMMM, Rolim HML, Ferreira PMP, Kamal MA, Pieczynska MD, Das N, Gupta VK, Mocan A, Dos Santos Andrade TJA, Singh BN, Mishra SK, Atanasov AG, Melo-Cavalcante AAC. A comprehensive review on biological properties of citrinin. Food Chem Toxicol. 2017 Dec;110:130-141. doi: 10.1016/j.fct.2017.10.002. Epub 2017 Oct 7. PMID: 28993214.
- Hope J. A review of the mechanism of injury and treatment approaches for illness resulting from exposure to water-damaged buildings, mold, and mycotoxins. Scientific World Journal. 2013 Apr 18;2013:767482. doi: 10.1155/2013/767482. PMID: 23710148







