Antibiotic Synergism: More Bang for Your Bug, by ShepherdFarmerGeek

Introductory Disclaimer: I am not a doctor and this is not professional medical advice for treating any medical condition. Improperly using antibiotics – too much or too little – could lead to illness, injury or death. Do the research and draw your own conclusions – the information in this article will help you get started. Don’t resort to using privately purchased antibiotics as long as professional medical care is available.


Synergy is “the interaction or cooperation of two or more …substances… to produce a combined effect greater than the sum of their separate effects.”

Why you might want antibiotic synergism:

  1. In order to take less antibiotic to minimize effects on intestinal flora (i.e., killing off your beneficial bowel bacteria) and reduce toxicity
  2. To treat a difficult/advanced infection or resistant bacteria
  3. To stretch and conserve your antibiotic supply by being able to use less antibiotics for the same effect
  4. To compensate for the fact that you don’t have a more advanced antibiotic and must make do with available varieties of “fish antibiotics” or other non-traditional sources
  5. To speed the healing process and return the patient to service sooner
  6. To wipe out all of the disease-causing bacteria without leaving resistant ones behind to cause a second infection.

Probably the best-known example of synergism in general is that between grapefruit and statins, but in fact grapefruit can increase or decrease absorption, bioavailability, and duration of availability of 85 drugs. And one glassful of juice can have an effect for up to three days.

Want to know all the fascinating things grapefruit does? Then read this and this.

There was even talk about combining grapefruit with (some) statins in a single pill to allow greater medication effect with a lower drug dose. What scuttled that plan, so far as I can tell, is that variations in individual genetics and personal biochemistry make predicting the degree of synergism impossible, not to mention that grapefruit could synergize other medications that the patient is taking as well!


As modern medicine began to treat malaria parasites (“the most deadly disease in the world,” killing nearly 500,000 people annually), the parasites began to develop a resistance to the most commonly used medications (including quinine and doxycycline). Now, a new approach called “Artemisinin Combination Therapy” (ACT) uses an herbal extract of the sweet wormwood plant (which also kills the malaria parasite by itself) at a 50/50 concentration with a known antiparasitic drug, and has been proven superior to using just one medication at a time (monotherapy). Synergism!

Synergism is happening all the time between the foods and supplements we eat and the medications we take. We’re just not used to the idea that it can happen with antibiotics and we’re not used to the idea that we can use this effect to help us under difficult austere medical conditions.


A variety of things will influence how well the synergism happens. Patients under stress, not properly hydrated, malnourished, or injured all have modified biochemistry as the person’s body attempts to adapt and heal. You already know that how a person’s body reacts to medications will be affected, but these factors also affect the degree of synergism.

If you’re just looking for a pill to pop, sorry, it won’t work that way. That’s not safe. These synergists all:

(a) have effects of their own, separate from any synergism, and

(b) they may affect other medications you’re taking for other medical problems, and

(c) their effect will all be dependent on the weight of the person/victim/patient, the amount of antibiotic you have to work with, and the amount and purity/quality of the synergist herb you’re using!

Because of this, and the fact that everyone’s biochemistry is slightly different, you’ll want to start small and slowly increase what you’re using as a synergist until you’re seeing the effects you want and not seeing dangerous side effects. This is what the term “titrate” frequently refers to – continuously and carefully measuring and adjusting the dose.


The Journal of Alternative Medical Research has a lengthy article about synergy that covers diabetes, cancer, mental conditions, heart conditions, and more. That entire article might be worth printing and keeping in your medicine cabinet for future reference! And note, again, how well researched this topic has been. There are 127 endnotes!

If we unpack some of the Latin plant names (below) you may begin to recognize some familiar supplements and sources. But note this! There is here no discussion of dosage.

This article is simply documenting the phenomenon and warning that synergism could create overdoses and other issues when taking prescription medications. Take the warnings seriously, but, in a collapse of our country’s financial or medical systems – in a catastrophe – these synergisms could be very helpful to know, if used wisely.

Here is their section about “antibiotics” in its entirety. Article footnote numbers and my comments are in brackets [ ] and I have bolded the synergist so you can see that some of these are very familiar:

“There have been reports where an herbal drug or its extract given along with an antibiotic has enhanced the antibacterial effect of the latter. Synergistic effect of grape seed extract (Vitis vinifera) with amphotericin B against disseminated candidiasis due to Candida albicans has been reported which indicated the combination can reduce more than 75% of amphotericin dose [33]. A synergistic combination for multi drug resistant Salmonella enterica serover typhi of aqueous fruit solution of Cassia fistula [from the Asian Golden Shower Tree] and amoxicillin has been reported [34]. Synergistic activity of methanolic extract of Thespesia populnea flowers [Portia tree / Pacific Rosewood] with oxytetracycline was observed with highest synergism rate against Shigella boydii [35]. A n-hexane fraction [extract] of Smallanthus sonchifolius [Yacón, a species of daisy from South America] showed more effective antimicrobial activity against methicillin-resistant Staphylococcus aureus strains under light. Synergistic effect of the fraction with ampicillin or oxacillin was observed [36]. A synergistic antimicrobial effect of garlic (Allium sativum) with ciprofloxacin in chronic bacterial prostatitis rat models has been reported [37]. Synergism between the extracts of Eugenia uniflora [Suriname Cherry] and E. jambolanum [Jambolan] and gentamicin was demonstrated for antimicrobial activity against two stains of Escherichia coli [38]. In a vector control programme study extracts of Eugenia jambolana and Solidago canadenesis [Canadian Goldenrod] showed synergistic effect with the chemical insecticide deltamethrin against dengue vector [mosquito] Aldes aegypti [39]. Proven scientifically to have antiplasmodial effects, leaves of Azadirachta indica [Neem tree] showed potentiated reduction of parasitemia and increased cure rate when given in combination with [extract of Artemisinin] artesunic acid [40]. The leaf extracts of Ocimum sanctum [Holy Basil] was reported to enhance in vitro antibacterial activity of chloramphenicol and trimethoprim against Salmonella enterica serovar typhi, showing synergism [41]. The essential oil of Ocimum sanctum had antifungal effect against various Candida isolates, and showed synergy with established azole antimycotics [antifungals] flucanazole and ketoconazole [42].

Propolis, a honey bee product has been intensively investigated for its antimicrobial activity. Recently, propolis has shown in vitro synergism with antibiotics acting on bacterial DNA (ciprofloxacin, norfloxacin) [43] and on ribosomes (chloramphenicol, tetracycline and neomycin) [44] against Salmonella enterica serovar typhi. [the bacteria responsible for Typhus]

A mention may be made here of a phyto-synergy between two parts of the same plant. The hydrodistilled leaf essential oil and extract of bark, root, leaf of Croton gratissimus [Lavender Croton, an African plant] were essential for antimicrobial activity independently and in combination. The result indicated greatest synergy in root and leaf combination against Bacillus cereusCandida albicans and Cryptococcus neoformans [45]. The methanolic extracts of resin of Ferula assafoetida [an Indian spice], rhizome of Zingiber officinale [Ginger root] and root of Gylcyrrhiza glabra [Licoricewere studied for antimicrobial efficacies independently and in combination against a number of microorganisms. The result indicated a better antimicrobial effect in combination extract than in individual providing evidence of synergism [46].

Natural products, which are plant secondary metabolites formed by enzymatically governed biosynthetic process, are bestowed with various biological activities. There are many reports on synergistic interactions between natural products formed within the same plant, natural product with a natural product from different sources, or natural product with drugs. A classical example of natural products of the same source acting synergistically is of berberine (8) with 5′-methoxyhydnocarpin (9) [a Berberine extract, also found in Goldenseal, commonly taken as an immune booster]. Berberine, a hydrophobic alkaloid is a weak antibacterial agent but a combination of berberine with 5′-methoxyhydrocarpin is a potent antibacterial agent [47], both of which are produced by berberry plants.

Several of synergistic interactions of the secondary metabolites of plants with antibiotics have been discussed [48]. The antibacterial action of antibiotics has been enhanced synergistically by natural products such as corilagin from Arctostaphylos uva-rvsi [49] [Uva Ursi / Bearberry, more commonly used to heal kidneys], baicalin from Scutellaria amoena [50,51] [Skullcap, a popular medicinal herb], carnosol and carnosic acid from Salvia officinalis [52] [common Sage]. Recently, phlorotannins from Eisenia bicyclis [53] [a Japanese sea kelp], curcumin from Curcuma longa [54] [Turmeric], eugenol from Eugenia aromatic [55] [Cloves] have been reported to exhibit synergistic with antibiotics.

Helvolic acid, a metabolite obtained from a strain Aspergillus sp 136 [a species of mold] showed synergistic effect with penicillin which was three times that of clavulanic acid [commonly combined with Amoxicillin and sold as Augmentin] with penicillin [56]. Methylglyoxal, a dicarbonyl natural compound obtainable from Manuka honey produced from Manuka flowers in New Zealand [57], has exhibited distinct and statistically significant synergism with piperacillin [a Penicillin antibiotic] against Pseudomonas aeruginosa [58].”

And there are synergists that enable anti-fungal medications or that have powerful anti-fungal effects all by themselves. Supplements such as Berberine, Garlic, Chinese Licorice and Thyme. So take heart, if you don’t have one of the synergist supplements you probably have another one that will work as well if carefully employed!

And there are so many synergists, some of them unique to only certain parts of the world, some of them perhaps even growing wild in your region, that to list them all in an article like this is not possible.


Antibiotics combinations can be classified as synergistic (if the drugs interact to increase each other’s effect), antagonistic (if their combined effect is less than the most effective drug used individually) or additive (if they do not interact).

Well, we don’t want an antagonistic interaction. But sometimes an antibiotic drug will synergize with another antibiotic drug. The antibiotics used in this study were erythromycin and doxycycline (both available from veterinary supply or overseas):

Antibiotics can also be used in simple combination to cover the weakness or shortcomings of one antibiotic you have with another antibiotic that has a different action. The combination might not actually be synergizing, just combining. This article lists 21 different combinations and their outcome.


Many essential oils and herbs have antibacterial, antiviral, or antifungal properties on their own, and some of them are synergistic as well. There are whole books written about how to find them, prepare them and use them.

  • Garlic (Allicin)
  • Pomegranate rind extract
  • Organosulfur compound in Cruciferous vegetables i.e.: cabbage, cauliflower, broccoli, Brussel sprouts…
  • Juniper Berry extract
  • Guava leaf extract and bark
  • Manuka Honey
  • Clove extract
  • Cinnamon extract
  • Fennel oil extract
  • Tea Tree oil
  • Oregano Oil
  • Certain probiotic strains from breast milk
  • Cranberry
  • Grapefruit seeds
  • Curcumin from Turmeric
  1. There are many, many herbs and plants that interact with antibiotics synergistically.
  2. Many of them are not available as supplements or extracts or oils commercially in the United States, but …many others are.
  3. Even if a plant is identified as coming from India or Brazil or the Mediterranian region it doesn’t mean that it isn’t available in the United States either as an extract or as the plant itself (some of these plants are ornamental).
  4. If you’ve got an antibiotic that you need to synergize, if it’s not mentioned specifically here it doesn’t mean that an herb you have on hand won’t synergize it. The moderate number of antibiotics available to you, and the large number of potential synergists, means there can be a lot of workable synergisms and you’re just going to have to (carefully!) experiment. Start with the well-known and readily available, standardized-strength synergists – Berberine, Garlic, Turmeric, Propolis, Ginger, Neem, Grape Seed Extract, etc.
  5. Identify the effects and side effects of your herbal supplement all on its own first. Are those consistent with the effects you want to achieve? (You’re not fighting an infection and also inadvertently dangerously turning down their blood pressure?) Will your supplement also interact with other medications the person is getting? Proceed with caution!

Antibiotic synergy is a valuable tool in your medical arsenal for when you’re deep in the wilds and trying to treat an injured person who is still days from professional medical care, or when trying to help a family member or friend through an infection when they’ve been shut out of the medical system over their COVID vaccination status or finances or insurance, or when it’s TEOTWAWKI and it’s up to you (and God) to save someone’s life when chaos is everywhere – a tool in your toolkit.

Trust God. Be prepared. We can do both.