The Art & Science of Herbal Formulation: Single Herbs, Blends & How They Work Together
discover how herbs interact and what makes a formula truly work
One of the things I love most about herbalism is how it lets us tap into something that feels a little like ancestral magic—but in a totally scientific way.
Hear me out.
Most of us, at some point in childhood, made “potions” out of crushed-up leaves, mossy sticks, weird-looking rocks, and a generous scoop of mud. Maybe it was a healing elixir, a secret cure, or a mystical brew meant to save the imaginary villagers who depended on your skills. You’d stir it all together in an invisible cauldron over the world’s hottest non-existent fire, mixing with all the seriousness of an apothecary at work.
No? Just me? Well, my imaginary village was thriving, so…
Anyway—back to reality.
Here’s the thing: I genuinely believe the act of making natural medicine is woven into our DNA, passed down through countless generations. Until very recently, knowing how to work with plants wasn’t just a skill—it was essential for survival. If our ancestors didn’t have at least a basic understanding of plant medicine, we wouldn’t be here.
Let that sit for a second.
And that ancestral instinct—to gather, mix, and create medicine—never really leaves us.
We start as kids just playing in the backyard.
Let's keep making magic and medicine in the garden, in the kitchen, and in the apothecary.
What to Expect in This Post
Alright, so this post will give you the basics of formulation vs. working with single herbs, show you how Traditional Chinese Medicine approaches formulation, and break down the different herb-herb interactions you might come across.
Then, Friday’s post for The Buffalo Herbalist Community will take things even further—how do we actually create formulas? What do we, as herbalists, need to take into account? We’ll go over:
Sample formulas and why they work
A formula blueprint to guide your own creations
Dosing considerations for safety and effectiveness
If all that sounds good and juicy, make sure to upgrade to paid so you don’t miss it!
The Science and Tradition of Herb-Herb Interactions
When it comes to formulation, one of the biggest mistakes people make is assuming that simply adding herbs together based on their known actions will result in a formula where all those actions show up equally—but that’s not how it works.
Take this example from The Modern Herbal Dispensatory:
“If one mixes an herb that stimulates the peristalsis of the colon with an herb that restrains the peristalsis of the colon, one cannot claim that the mixture will cure both diarrhea and constipation.”
See the issue? It’s like trying to hit the gas and brake at the same time. Just as the action of a single herb is not the same as the sum of its individual constituents (a common misconception in herbal medicine), a formula’s action is different from the sum of its individual herbs. It’s a little like cooking—ingredients interact, and the final dish is more than just the flavors you started with.
Now, you might be thinking:
"I don’t really plan on formulating... do I even need to know this?"
If you’re blending teas? Making tinctures with more than one herb? Even just mixing two herbs together for a remedy? Congratulations—you’re formulating! And those herbs will interact with each other. (More on the different types of interactions later in this post.)
Understanding Herb-Herb Interactions
Herbal medicine has long been practiced through both single-herb applications and complex multi-herb formulations, each carrying its own therapeutic potential and interactions. While modern research has extensively studied herb-drug interactions, much less attention has been given to herb-herb interactions, despite their foundational role in traditional medicine. These interactions can be classified into synergistic, additive, or antagonistic effects, all of which influence both efficacy and safety.
The term "synergy" originates from the Greek word synergos, meaning "working together." According to the McGraw–Hill Concise Dictionary of Modern Medicine, synergy (or synergism) refers to the cooperative interaction between two or more components within a system, resulting in a combined effect that exceeds the sum of their individual contributions.
Understanding how herbs interact with each other is crucial—not just for making herbal medicine more effective, but for ensuring it’s used safely.
The Traditional Chinese Medicine (TCM) Approach to Herb Combinations
I wouldn’t claim to be an expert in Traditional Chinese Medicine (TCM), or really knowledgeable at all, BUT its structured approach to herbal combinations is one of the most fascinating frameworks for understanding herb interactions. Unlike modern pharmacology, which tends to isolate active compounds, TCM prescribes herbs in specific groupings, ensuring they work harmoniously within a formula.
Think of a TCM prescription like an imperial court, where each herb plays a distinct role:
The "Emperor" Herb – The chief herb that targets the primary condition. (Example: Ephedra sinica in the classic Decoction of Ephedra, used for respiratory conditions.)
The "Minister" Herb – Supports the emperor herb, either reinforcing its effect or addressing secondary symptoms. (Example: Cinnamomum cassia, which enhances circulation and expels cold.)
The "Assistant" Herb – Enhances the formula, reduces toxicity, or balances warming/cooling properties. (Example: Prunus armeniaca, which helps ventilate the lungs.)
The "Servant" (or "Guide") Herb – Directs the formula’s effects to specific organs and harmonizes its properties. (Example: Glycyrrhiza uralensis, licorice root, which smooths the blend and mitigates harsh effects.)
From a pharmacological perspective, these structured combinations likely involve pharmacokinetics, pharmacodynamics, and multi-target effects, aligning with modern concepts of polypharmacy.
How Herbs Interact: The Science Behind Synergy
Beyond traditional frameworks, modern research highlights several ways in which herbs modify each other’s effects:
Synergistic Multi-Target Effects
Some herbs act on multiple biological pathways, amplifying their therapeutic effects.
Example: Hypericum perforatum (St. John’s Wort) – Interacts with multiple neurotransmitter systems, enhancing mood regulation.
Example: Cannabis sativa (cannabis extract) – Modulates cannabinoid receptors, affecting various physiological processes.
Modulation of Pharmacokinetics and Bioavailability
Certain herbs enhance absorption, metabolism, or circulation, improving the effectiveness of other compounds.
Example: Panax ginseng (ginseng) – Influences drug metabolism via cytochrome P450 enzymes.
Example: Citrus × paradisi (grapefruit) – Alters bioavailability by inhibiting enzymes that break down active compounds.
Interference with Resistance Mechanisms
Some herbs counteract microbial or cancer cell resistance, restoring treatment efficacy.
Example: Flavonoids like quercetin and apigenin – Found in Pelargonium graveolens (geranium) essential oils, these compounds exhibit anti-resistance properties.
Detoxification & Protection Against Toxic Effects
Certain herbs help neutralize or eliminate toxins in the body.
Example: Silybum marianum (milk thistle) + Glycyrrhiza glabra (licorice) – Both are widely used for liver protection, reducing damage from toxins and medications.
Reinforcement: When Two Herbs Amplify Each Other
Reinforcement occurs when herbs with similar medicinal properties are used together to increase efficacy.
Example: Ephedra sinica + Cinnamomum cassia – In Decoction of Ephedra, cinnamon increases peripheral blood flow, reinforcing ephedra’s diaphoretic (sweat-inducing) effect, enhancing fever reduction.
Example: Corydalis yanhusuo + Curcuma phaeocaulis – In the Yanhusuo San formula, Corydalis promotes qi movement, strengthening Curcuma’s blood circulation effects to relieve pain and blood stasis.
Example: Lonicera japonica + Forsythia suspense – A classic heat-clearing pair, prescribed for colds and flu, helping the body eliminate toxins and pathogens.
A modern parallel? The HAART approach in HIV therapy, where multiple antiviral drugs are combined to improve efficacy.
Potentiation: When One Herb Boosts Another
In potentiation, one herb is the principal agent, while the other serves as a booster to strengthen its effect.
Example: Panax ginseng + Aconitum carmichaelii – In Shenfu Tang, ginseng replenishes qi, while aconite warms the body, making it effective for shock recovery.
Example: Paeonia lactiflora + Glycyrrhiza uralensis – Used in Shaoyao Gancao Decoction for pain relief and muscle spasms, with studies showing a synergistic pain-relief effect when combined in a 3:1 ratio.
Restraint & Detoxification: Neutralizing Toxicity
Many herbs are inherently toxic, but traditional medicine often pairs them with detoxifying herbs to reduce adverse effects.
Example: Tripterygium wilfordii (lei-gong-teng) – Used in TCM for autoimmune disorders, but must be carefully formulated due to its toxicity.
Example: Pinellia ternata + Zingiber officinale (ginger) – Pinellia tuber is highly irritant, but when combined with ginger, its toxicity is neutralized while retaining its therapeutic effect.
The Need for Further Research
Despite centuries of traditional knowledge, modern research on herb-herb interactions is still in its infancy. While pharmacodynamic and pharmacokinetic studies of herb-drug interactions are growing, far fewer studies focus on how herbs influence each other when used together.
By examining both traditional frameworks and scientific research, we can optimize herbal formulations, ensuring they remain both safe and effective. Whether through TCM’s structured prescriptions or modern pharmacological insights, herb-herb interactions remain a critical component of herbal medicine—one that deserves deeper exploration.
My Thoughts
Herbal formulation is more than just mixing herbs together and hoping for the best—it’s about understanding how plants interact, how to balance their effects, and how to create something greater than the sum of its parts. Whether you’re working with a single herb or crafting a multi-herb blend, intention and knowledge matter.
By learning the different types of herb-herb interactions, we can make our herbal remedies more effective, safer, and better suited to individual needs. Traditional medicine systems like TCM have long understood this, and modern research is slowly catching up.
The key takeaway? Every herb you add to a formula changes the outcome—so choose wisely, experiment thoughtfully, and most importantly, trust the process.
If you enjoyed this post, like, comment, restack, and share! It helps more people discover this space, and I’d love to hear from you.
💬 Drop a comment below with your favorite herbal formulas! Whether it’s a simple two-herb tea blend or a complex multi-herb creation, let’s swap ideas and learn from each other.
Until next time—happy formulating! 🌿✨
-Agy
What’s Coming Friday for Paid Subscribers?
This Friday’s post for The Buffalo Herbalist Community will take everything we covered today and put it into practice. We’ll be going deeper into:
- How to actually build an effective formula
- The key factors to consider when creating blends
- Sample formulas & why they work
- A formula blueprint you can use
- Dosing considerations for safety & effectiveness
If you want the hands-on, practical side of formulation, make sure you’re subscribed to the paid tier so you don’t miss out!
Bibliography:
Che, C., Wang, Z., Chow, M., & Lam, C. (2013). Herb-Herb Combination for Therapeutic Enhancement and Advancement: Theory, practice and Future Perspectives. Molecules, 18(5), 5125–5141. https://doi.org/10.3390/molecules18055125
Easley, T., & Horne, S. (2016). The modern herbal Dispensatory: A Medicine-Making Guide. North Atlantic Books.
Niu, J., Straubinger, R. M., & Mager, D. E. (2019). Pharmacodynamic Drug–Drug interactions. Clinical Pharmacology & Therapeutics, 105(6), 1395–1406. https://doi.org/10.1002/cpt.1434
Pezzani, R., Salehi, B., Vitalini, S., Iriti, M., Zuñiga, F., Sharifi-Rad, J., Martorell, M., & Martins, N. (2019). Synergistic effects of plant derivatives and conventional chemotherapeutic Agents: an update on the cancer perspective. Medicina, 55(4), 110. https://doi.org/10.3390/medicina55040110
This is very valuable!!! Great work.
Beautifully written. ❤️