That is the question of the ages!
We know it works—but how?
Well, science is finally beginning to figure that out. Dr. Iris Bell, MD, Ph.D. (University of Arizona College of Medicine) explains:
Homeopathic medicines are not conventional drugs. Conventional drugs act via biochemical, mechanistically targeted, specific direct local effects. In contrast, in this complexity model, the correct homeopathic medicine serves as a low-dose stimulus or individualized signal for inducing patterns of functional adaptive changes globally and locally in the body. The homeopathic signal (otherwise known as “the remedy”) captures and conveys a low or weak "dose" of the salient complex disease frequency information to the body, thereby setting in motion personalized…responses to reverse the disease.
What makes homeopathic remedies so unique—so different from ordinary drugs?
According to Dr. Bell and her colleagues, the unique manufacturing process by which remedies are made creates complex nanostructures (super tiny particles) that can communicate/signal information to living systems…
The difference between higher and lower potencies? Higher potency remedies endure a greater degree of agitation or succussion during manufacture than each lower potency—inevitably leading to the generation of increasingly smaller nanostructures. The smaller the size, the greater the surface area/reactive surface of the particle.
How homeopathy works… according to the evidence:
…homeopathic treatment involves treating the individual patient literally with a quantitatively low dose of his or her own current holistic biological disease state information (in the form of the homeopathic remedy ) at the nano-scale level… This first step initiates (a) cascade of adaptive biological signaling (within the recipient organism)… once the simillimum ( most similar) homeopathic signal (remedy) interfaces and acquires its personalized biological identity from the recipient's own bodily fluids (by acquiring a protein shell from the patient's blood plasma), the…biological signaling networks of the body can take over.
All of this leads to:
… modulating the biology of symptoms and healing via functional changes in neural, immune, and inflammatory pathway networks and mediators… These adaptations are all in the service of optimizing the individual's fitness to survive… 
Ok. Now in simpler terms: homeopathic remedies are made from very dilute solutions of medicinal materials.
So, you ask, if they are so dilute, how can they be effective?
Thanks to the work of over a dozen research labs in the U.S., France, Italy, Russia and India, we now know that the homeopathic remedy manufacturing process produces significant numbers of nanoparticles of the medicinal substance every time a remedy is made. Nanoparticles are tiny—ranging in size from 1 nanometer (nm) on a side up to 1000 nm or more.
What makes a nanoparticle special?
Science has confirmed that nanoparticles have properties quite unlike ordinary bulk materials (like OTC and prescription drugs), providing greater bioavailabilty (the ability of a substance to be used by the body) with improved rates of absorption and enhanced catalytic ability for chemical and biochemical reactions .
Let’s go back to Dr. Bell:
According to current research, when a living creature encounters an external or internal stressor (a bacterium, a virus, an environmental toxin, a nanoparticle, and emotional shock, etc.), its complex adaptive system makes adjustments impacting the entire organism in an attempt to maintain a balanced state and improve the chances of survival.
Adaptations in a living system are all in the service of optimizing the individual's fitness as (a complex adaptive system) to survive in an environment that includes encounters with ever-changing larger and smaller stressors.
Disease occurs when stressors reach a certain threshold, forcing the organism into an unnatural and unbalanced state.
How does homeopathy help?
Classical homeopathy focuses on treating the patient as an indivisible whole (living system). For homeopathy, the "diagnosis" (involves the) determination of the one medicine that best matches (is most similar to) the whole, integrated, bio-psychosocial symptom picture or pattern (state) of the patient at the time of treatment.
…classical homeopathy requires one unified diagnosis (the medicine picture [state of the patient] in the present time), and treatment with the single medicine that best captures the information pattern of a similar, multi-subsystem pattern of symptoms. Homeopathic symptoms (the symptoms of each patient) are manifestations of a singular, pervasive, emergent disturbance of the (whole) individual as a whole system or network of networks, not of a specific body part or biological mechanism in isolation.
According to Dr. Bell, when used correctly, the individually salient (relevant), low dose of the correct homeopathic medicine (simillimum) triggers a disproportionately large-magnitude organism-wide reversal of multiple symptoms (disease) . Again to simplify—remedies trigger the body’s innate ability to heal. They work with the body—rather than against it, the way most ordinary drugs do (ie, anti-inflammatories, anti-biotics, etc.)
Truth is—homeopathy is a gift to humankind. It’s fully compatible with the known laws of healing; it works synergistically with the health-giving/health-protecting microbes in the body  and the immune system , and it’s consistently shown vastly superior environmental sustainability. In short, homeopathy provides you and your family with one of the safest and most efficacious methods of treating and resolving illness.
* As with any medical condition, consult with your physician if you have any concerns about the severity of your problem as it may first require medical diagnosis and/or intervention and monitoring.
About Dr. Iris Bell: Dr. Bell is internationally renowned for her work in the field of integrative medicine. She is a brilliant researcher, having received her Bachelor of Science degree from Harvard (Magna Cum Laude) and her M.D. and Ph.D. from Stanford University. She was also a National Science Foundation Predoctoral Fellow.
About Dr. Lisa Samet:
Dr. Lisa Samet N.D. provides Washington Homeopathic Products with a regular column on using homeopathy for the family. She's a naturopathic physician who specializes in homeopathic medicine and she's a partner with Dr. Andre Saine N.D. Dr. Samet graduated from the Southwest College of Naturopathic Medicine in 1998 and has been practicing in Montreal since then. She was born and raised in New York.
Dr. Samet has chosen to focus on homeopathy because in her experience it is the deepest healing modality available in that it does not just soothe or palliate symptoms but can actually stimulate the body to start to heal itself. Dr. Samet sees patients in her Montreal office as well as long distance using Skype. Learn more here: Dr. Lisa Samet. You can follow her on Facebook as well.
 Bell, I., The Complexity of the Homeopathic Healing Response Part 1: The Role of the Body as a Complex Adaptive System in Simillimum-Initiated Recovery from Disease. Homeopathy 2020; 109(02): 042-050
 C. Buzea, I. I. Pacheco and K. Robbie: Nanomaterials and nanoparticles: sources and toxicity. Biointerphases
 Bellavite P, Conforti A, Pontarollo F, et al. Immunology and Homeopathy. 2. Cells of the Immune System and Inflammation; Evid Based Complement Alternat Med. 2006 Mar; 3(1): 13–24. doi:10.1093/ecam/nek018