synergy
65 interactions related to synergy
vitamin a + vitamin d
Vitamins A and D share the same nuclear receptor partner, RXR, and work together to regulate gene transcription affecting immunity, bone metabolism, and epithelial health. Moderate intake of both supports balanced signaling, though very high doses of one can blunt the action of the other.
boron + magnesium
Boron supports magnesium retention and deposition in bone, and the two minerals jointly influence the activation of vitamin D. In rodent studies, boron supplementation reduced the metabolic abnormalities of magnesium-deficient diets and raised plasma magnesium levels.
vitamin d3 + vitamin k2
Vitamin D3 increases calcium absorption and stimulates production of vitamin K-dependent proteins (osteocalcin, matrix Gla protein) that themselves require K2 for activation. Co-supplementation supports bone density and may reduce vascular calcification compared with D3 alone.
coq10 + pqq
CoQ10 shuttles electrons in the mitochondrial electron transport chain to produce ATP, while PQQ activates PGC-1alpha to stimulate the biogenesis of new mitochondria. Used together they support both the quantity and efficiency of cellular energy production.
lemon balm + valerian
Lemon balm (Melissa officinalis) and valerian (Valeriana officinalis) both modulate the GABAergic system but through different mechanisms — valerian's valerenic acid acts directly on GABA-A receptors while lemon balm's rosmarinic acid inhibits GABA transaminase to preserve GABA in the synapse — and the combination has been studied for restlessness, dyssomnia, and sleep quality.
curcumin + ginger
Curcumin and ginger both inhibit NF-kB and COX-2 signaling, but ginger also independently blocks 5-lipoxygenase and contains gingerols and shogaols that suppress prostaglandin and leukotriene synthesis. A randomized trial of a turmeric-black pepper-ginger combination showed efficacy comparable to naproxen for chronic knee osteoarthritis pain.
niacin + coq10
Niacin (vitamin B3) is the precursor to NAD+ and NADH, the electron carriers that feed into Complex I of the mitochondrial electron transport chain where CoQ10 shuttles those electrons toward ATP synthesis. Together they support different stages of the same energy-producing pathway.
zinc + copper
Zinc and copper share an intestinal absorption pathway through metallothionein, so chronic high-dose zinc (50 mg or more daily) progressively depletes copper, causing anemia, neutropenia, and myelopathy. Co-supplementing copper at roughly 1 mg per 15 mg zinc preserves balance and allows long-term zinc use without copper deficiency.
calcium + magnesium
Calcium and magnesium work together in bone mineralization, muscle contraction, and nerve signaling, but they compete for absorption through the same intestinal transporters at high single doses. Maintaining a dietary calcium-to-magnesium intake ratio in the 2:1 to 3:1 range is associated with the highest bone mineral density and lowest osteoporosis risk.
boron + calcium
Boron reduces urinary calcium excretion and supports the hydroxylation of vitamin D into its active form, which in turn enhances intestinal calcium absorption. Postmenopausal women taking 3 mg/day of boron have shown reduced urinary calcium loss and improved markers of calcium retention.
potassium + magnesium
Magnesium is required for the Na/K-ATPase pump that maintains intracellular potassium, so magnesium deficiency causes refractory potassium loss that cannot be corrected by potassium alone. Co-supplementation of the two minerals produces additive reductions in systolic blood pressure and supports normal cardiac rhythm.
vitamin a + zinc
Zinc is required for the hepatic synthesis of retinol-binding protein, the carrier that mobilizes vitamin A from liver stores into circulation. Zinc deficiency lowers circulating retinol even when liver vitamin A is adequate, and combined supplementation outperforms either alone in deficient populations.
vitamin e + vitamin c
Vitamin C regenerates the active form of vitamin E by donating an electron to the tocopheroxyl radical that forms after vitamin E scavenges a lipid free radical. The pair extends antioxidant capacity at the lipid-water interface of cell membranes.
vitamin b6 + vitamin b12
Vitamin B6 (as pyridoxal 5'-phosphate) and vitamin B12 (as methylcobalamin) act as complementary coenzymes in one-carbon metabolism: B12 helps remethylate homocysteine back to methionine, while B6 routes excess homocysteine down the transsulfuration pathway to cysteine. Together they keep blood homocysteine within a healthier range than either nutrient does alone.
vitamin b6 + folate
Vitamin B6 and folate work in tandem within one-carbon metabolism: folate (as 5-MTHF) donates a methyl group to remethylate homocysteine, while B6 (as PLP) is the cofactor for serine hydroxymethyltransferase and cystathionine beta-synthase, supporting both the folate cycle and the transsulfuration route that disposes of excess homocysteine.
ashwagandha + magnesium
Ashwagandha modulates the HPA stress axis and lowers cortisol while magnesium acts as a cofactor for GABAergic and parasympathetic relaxation pathways, giving complementary mechanisms for sleep and stress support.
choline + vitamin b12
Choline (via its metabolite betaine) and vitamin B12 power the two parallel pathways that remethylate homocysteine to methionine: the choline-betaine-BHMT route and the folate-B12-methionine-synthase route. Adequate choline can compensate for low B12 or folate status by maintaining methylation through the BHMT pathway, supporting healthy homocysteine and SAMe levels.
acetyl-l-carnitine + alpha-lipoic acid
Acetyl-L-carnitine shuttles fatty acids into mitochondria for energy production while alpha-lipoic acid acts as a mitochondrial antioxidant and cofactor for energy-producing enzymes; in aged animal studies, the combination reversed mitochondrial decay and improved memory more than either alone.
l-theanine + caffeine
L-theanine, an amino acid from tea, smooths out caffeine's stimulant effects by promoting alpha-wave brain activity associated with relaxed alertness, while caffeine blocks adenosine receptors to increase arousal — the combination has been shown in multiple human trials to improve sustained attention and reaction time more than either alone.
vitamin b1 + magnesium
Magnesium is the required cofactor that converts thiamine (vitamin B1) into its active coenzyme form, thiamine pyrophosphate (TPP). Without adequate magnesium, thiamine cannot activate properly, so supplementing thiamine in a magnesium-deficient person produces little benefit until magnesium is restored.
phosphatidylserine + omega-3
Phosphatidylserine bound to omega-3 fatty acids (particularly DHA) is more readily incorporated into neuronal membranes than either nutrient alone, supporting membrane fluidity, neurotransmitter release, and memory consolidation. Clinical trials of PS-DHA preparations show improvements in memory and sustained attention in older adults with subjective memory complaints.
ashwagandha + l-theanine
L-theanine acts within 30-60 minutes to increase alpha brain waves and modestly elevate GABA, producing immediate relaxation without sedation. Ashwagandha builds resilience over weeks by lowering cortisol and modulating the HPA axis. Combined, the pair delivers both fast-acting calm and longer-term stress resilience. Direct combination trials in humans are limited; the rationale is mechanistic.
gaba + l-theanine
GABA and L-theanine combined produce a synergistic effect on sleep onset and quality that neither produces alone. A 2019 study in Pharmaceutical Biology showed the mixture decreased sleep latency by roughly 20% and increased non-REM sleep duration by roughly 20% compared to either ingredient alone. A 2023 human study found improvements in sleep quality scores with the combination.
omega-3 + curcumin
Omega-3 fatty acids (EPA and DHA) and curcumin both reduce inflammation through complementary pathways — omega-3s alter cell membrane composition and produce specialized pro-resolving mediators, while curcumin directly inhibits NF-kB and inflammatory cytokine signaling.
melatonin + magnesium
Melatonin signals the brain that it is biological night through MT1 and MT2 receptors in the suprachiasmatic nucleus, while magnesium acts as a NMDA antagonist and GABA-A agonist, helping the nervous system actually relax around that signal. A double-blind RCT in nursing home residents with primary insomnia (Rondanelli 2011) found that nightly melatonin 5 mg + magnesium 225 mg + zinc 11.25 mg significantly improved sleep quality, ease of falling asleep, and morning alertness versus placebo.
passionflower + lemon balm
Passionflower (Passiflora incarnata) contains flavonoids that act as positive modulators at the GABA-A receptor benzodiazepine site, while lemon balm (Melissa officinalis) inhibits GABA transaminase, the enzyme that breaks down GABA. The two herbs raise GABAergic tone through complementary mechanisms - one boosts receptor activity, the other extends GABA's half-life - which is the basis for several traditional anxiolytic and sleep formulas.
glutathione + vitamin c
Vitamin C reduces oxidized glutathione (GSSG) back to reduced glutathione (GSH) via the ascorbate-glutathione cycle, while glutathione in turn regenerates oxidized vitamin C (dehydroascorbate) back to ascorbate. The two antioxidants mutually recycle each other and maintain cellular redox balance.
nac + vitamin c
NAC supplies cysteine for glutathione synthesis while vitamin C reduces oxidized glutathione (GSSG) back to its active form (GSH) and directly scavenges aqueous-phase free radicals. The two work together to maintain a high GSH:GSSG ratio inside cells.
curcumin + boswellia
Curcumin inhibits NF-kB and dampens COX-2 transcription while boswellic acids (particularly AKBA) selectively block 5-lipoxygenase and leukotriene synthesis. Together they suppress two non-overlapping arms of the inflammatory cascade, giving better symptom relief in osteoarthritis than either alone.
nac + selenium
NAC supplies cysteine for glutathione synthesis while selenium is the obligate cofactor in glutathione peroxidase enzymes, which use glutathione to neutralize peroxides. Without adequate selenium, the glutathione that NAC helps produce cannot be fully utilized in peroxide detoxification.
hyaluronic acid + collagen
Hyaluronic acid and collagen are the two dominant structural components of the extracellular matrix in skin and synovial fluid — collagen provides tensile strength while hyaluronic acid binds water and provides cushioning. Oral collagen peptides have been shown to upregulate fibroblast production of hyaluronic acid, and clinical trials of combined oral HA plus collagen formulations show additive improvements in skin hydration and elasticity.
msm + glucosamine
MSM (methylsulfonylmethane) provides bioavailable sulfur required for the synthesis of glycosaminoglycans and connective tissue, which complements glucosamine's role as a substrate for proteoglycan production. A 12-week randomized trial in knee osteoarthritis found the combination of MSM plus glucosamine produced greater reductions in pain and swelling than either supplement alone.
collagen + vitamin c
Vitamin C is an essential cofactor for prolyl and lysyl hydroxylase, the enzymes that hydroxylate proline and lysine residues during collagen synthesis and stabilize the triple-helix structure. Taking collagen peptides with vitamin C supplies both the amino acid building blocks and the enzymatic cofactor required to convert them into functional new collagen.
hawthorn + coq10
Hawthorn (Crataegus) flavonoids improve myocardial contractility and coronary blood flow through mild ACE inhibition and vasodilation, while CoQ10 supports cardiac ATP production in the electron transport chain. Together they address both the mechanical and metabolic demands of the failing or stressed heart.
omega-3 + vitamin e
Omega-3 fatty acids (EPA and DHA) are polyunsaturated and highly susceptible to oxidation, which can blunt their cardiovascular and anti-inflammatory benefits. Vitamin E (mixed tocopherols) acts as a lipid-soluble antioxidant that protects omega-3 fatty acids from peroxidation both during storage and after absorption.
l-arginine + l-citrulline
L-arginine is the direct precursor to nitric oxide but is heavily degraded by intestinal arginase and first-pass hepatic metabolism. L-citrulline bypasses this metabolism and is converted to L-arginine in the kidneys, sustaining elevated plasma arginine for hours rather than minutes when the two are combined.
curcumin + fat
Curcumin is a lipophilic molecule with very low water solubility, and dietary fat dramatically improves its dissolution and incorporation into bile acid micelles for intestinal absorption. Lipidic formulations and meals containing fat increase curcumin's plasma exposure compared with intake on an empty stomach.
iron + vitamin a
Vitamin A and beta-carotene improve absorption of non-heme iron from plant foods by forming soluble complexes with iron that protect it from binding to phytates and polyphenols in the gut. In a controlled human study, vitamin A roughly doubled iron absorption from rice and increased absorption from wheat and corn.
fat-soluble vitamins + dietary fat
Vitamins A, D, E, and K depend on bile acid micelle formation in the small intestine for absorption, and that process requires dietary fat as a trigger for bile secretion. Taking these vitamins without fat reduces absorption efficiency substantially, with studies on vitamin D showing roughly 30-50% greater absorption when taken with a meal containing fat.
spermidine + resveratrol
Spermidine and resveratrol both induce autophagy but through different upstream mechanisms: spermidine inhibits histone acetyltransferases (lowering histone acetylation), while resveratrol activates the sirtuin SIRT1 (a deacetylase). The two converge on the acetylproteome and have been shown to synergize at low doses for autophagy induction and lifespan extension in model organisms.
turmeric + black pepper
Piperine, the active alkaloid in black pepper, inhibits hepatic and intestinal glucuronidation of curcumin and other compounds, and a landmark human study reported a 2000% increase in curcumin bioavailability when 20 mg piperine was co-administered with 2 g curcumin. This is one of the most cited absorption-enhancement combinations in the supplement literature.
resveratrol + quercetin
Quercetin inhibits the sulfotransferase and UDP-glucuronosyltransferase enzymes that rapidly clear resveratrol, prolonging its plasma half-life and free fraction. The two polyphenols also act synergistically on antioxidant and SIRT1-related longevity pathways in cell and animal studies.
caffeine + tyrosine
L-tyrosine is a precursor to dopamine and norepinephrine, and caffeine triggers their release; combining them can modestly improve cognitive performance under stress, fatigue, or sleep deprivation. The synergy is generally well tolerated, though it can mildly amplify caffeine's stimulant effects.
nad+ + niacin
Niacin (nicotinic acid) is a vitamin B3 precursor that the body converts to NAD+ via the Preiss-Handler pathway, so pairing oral niacin with direct NAD+ precursors can support cellular NAD+ pools through complementary biosynthetic routes. In a clinical study of mitochondrial myopathy, 1,000 mg/day niacin meaningfully raised muscle and blood NAD+.
lycopene + fat
Lycopene is a fat-soluble carotenoid whose absorption depends on incorporation into bile acid micelles, which require dietary fat. A landmark study showed adding olive oil to tomatoes increased plasma trans-lycopene by 82%, and avocado co-consumption with tomato salsa increased lycopene AUC 4.4-fold.
boswellia + omega-3
Boswellic acids inhibit 5-lipoxygenase to block pro-inflammatory leukotrienes, while EPA and DHA from omega-3s reduce arachidonic acid availability and serve as substrates for specialized pro-resolving mediators (resolvins, protectins) that actively turn off inflammation. The two ingredients suppress inflammation at different steps of the same lipid cascade, giving complementary anti-inflammatory coverage.
vitamin k2 + calcium
Vitamin K2 activates osteocalcin and matrix Gla protein, which bind calcium and direct it into the bone matrix while keeping it out of arterial walls. Calcium supplementation paired with adequate K2 supports bone density and reduces the risk of misplaced calcium in soft tissue.
l-theanine + magnesium
L-theanine increases alpha-wave activity, raises GABA, serotonin and dopamine, and crosses the blood-brain barrier readily, while magnesium acts as an NMDA antagonist and positive GABA-A modulator. Dasdelen et al (Frontiers in Nutrition, 2022) showed that a magnesium-L-theanine complex outperformed L-theanine alone for reducing sleep latency, restoring caffeine-suppressed slow waves, and increasing GABAergic and serotonergic receptor expression in rats.
vitamin b12 + folate
Vitamin B12 and folate are interdependent coenzymes in the methionine cycle: methylfolate donates a methyl group to homocysteine while B12 (methylcobalamin) is the required cofactor for methionine synthase, the enzyme catalyzing the reaction. Adequate intake of both is needed to lower homocysteine, support DNA synthesis, and prevent the neurologic damage that high-dose folate alone can mask.
niacin + tryptophan
Tryptophan is converted in the liver to niacin (vitamin B3) at a ratio of roughly 60 mg tryptophan to 1 mg niacin, so adequate dietary tryptophan reduces the niacin requirement and helps maintain NAD/NADP coenzyme pools. Niacin in turn spares tryptophan for serotonin and melatonin synthesis, supporting mood and sleep.
ginkgo + phosphatidylserine
Ginkgo biloba improves cerebral blood flow and has antioxidant effects; complexing it with phosphatidylserine substantially enhances absorption of its active terpene lactones and flavone glycosides. The Virtiva complex (ginkgo + phosphatidylserine) showed improved secondary memory and faster memory task performance versus ginkgo alone in a placebo-controlled crossover trial.
ashwagandha + reishi
Ashwagandha (Withania somnifera) downregulates the HPA axis and lowers morning cortisol, while reishi (Ganoderma lucidum) provides immunomodulatory beta-glucans and triterpenes that support parasympathetic tone. A 2025 randomized, double-blind, placebo-controlled trial in 499 healthy adults (Pham et al, Current Developments in Nutrition) found that 6 weeks of a reishi + ashwagandha supplement significantly reduced perceived stress versus placebo, without significant adverse events.
nac + glutathione
NAC (N-acetylcysteine) provides the rate-limiting cysteine substrate the body uses to synthesize new glutathione intracellularly, while supplemental glutathione directly replenishes the circulating and extracellular pool. The two work through complementary upstream-and-downstream mechanisms to support antioxidant defense and phase II liver detoxification.
magnesium + glycine
When magnesium is bound (chelated) to two glycine molecules as magnesium bisglycinate, the amino-acid carrier protects the mineral from binding with phytates and oxalates in the gut and shuttles it across the intestinal wall more efficiently, producing higher bioavailability and less GI upset than inorganic salts like magnesium oxide. Glycine itself is also an inhibitory neurotransmitter that may lower core body temperature and shorten sleep latency, so the pairing supports relaxation as well as absorption.
selenium + iodine
Iodine is the raw material for thyroid hormones T4 and T3, but selenium is required to build the deiodinase enzymes that convert inactive T4 into active T3 in peripheral tissues. Selenium also powers glutathione peroxidase, which protects thyroid follicular cells from the oxidative damage of iodine handling.
vitamin b6 + magnesium
Vitamin B6 enhances cellular uptake and retention of magnesium and supports magnesium-dependent enzyme activity, while magnesium is required for the conversion of B6 to its active PLP form. Clinical trials in PMS, stress, and anxiety show the combination reduces symptoms more than magnesium alone.
curcumin + quercetin
Quercetin inhibits the same UDP-glucuronosyltransferase and CYP3A4 enzymes that rapidly metabolize curcumin, raising its plasma exposure, and both polyphenols share complementary anti-inflammatory and antioxidant pathways. In vitro intestinal models and animal studies show the combination increases apical-to-basal uptake of curcumin and amplifies NF-kB pathway suppression.
choline + inositol
Choline and inositol are classic lipotropic nutrients: choline is required to package triglycerides into VLDL particles for export from the liver, while inositol contributes to phosphatidylinositol signaling and supports lipid metabolism. Combined, they reduce hepatic fat accumulation more than either alone in animal and small human studies.
garlic + hawthorn
Aged garlic extract lowers blood pressure through endothelial nitric oxide release, mild ACE inhibition, and antioxidant effects, while hawthorn flavonoids provide vasodilation, mild positive inotropy, and improved coronary flow. Together they act on complementary aspects of vascular tone and cardiac function in mild hypertension.
acetyl-l-carnitine + coq10
Acetyl-L-carnitine (ALCAR) shuttles long-chain fatty acids into the mitochondrial matrix where they can be beta-oxidized, and CoQ10 then carries the electrons generated by that oxidation through the electron transport chain. The two are functionally complementary along the same energy-production pathway, and combination products have shown benefits in mitochondrial-dysfunction contexts like chronic fatigue and drug-induced hepatotoxicity.
fisetin + quercetin
Fisetin and quercetin are structurally related flavonols with overlapping but distinct senolytic and anti-inflammatory mechanisms. Fisetin was identified in a Mayo Clinic screen as the most potent natural senolytic, while quercetin has been clinically tested as part of the dasatinib + quercetin senolytic combination, and the two together broaden the senolytic and antioxidant coverage.
pomegranate + ace inhibitors
Pomegranate polyphenols (pedunculagin, punicalin, gallagic acid) directly inhibit angiotensin-converting enzyme, and clinical trials show pomegranate juice lowers systolic and diastolic blood pressure on its own. Combined with prescription ACE inhibitors the effects can stack, potentially causing additive hypotension, dizziness, or hyperkalemia.
vitamin e + selenium
Vitamin E and selenium work as complementary antioxidants. Selenium is the cofactor for glutathione peroxidase, which clears lipid peroxides, sparing vitamin E. Vitamin E in turn prevents lipid peroxidation, reducing demand on the selenium-dependent enzyme.
saffron + curcumin
Saffron (Crocus sativus) and curcumin both have antidepressant effects through complementary mechanisms: saffron modulates serotonin reuptake and increases BDNF, while curcumin reduces neuroinflammation and supports monoamine balance via MAO inhibition and HPA-axis modulation. A randomized placebo-controlled trial in major depressive disorder showed the combination was effective in reducing depressive and anxiolytic symptoms.
rhodiola + ashwagandha
Rhodiola rosea and Ashwagandha are both adaptogens but act through different mechanisms: Rhodiola primarily provides an energizing, anti-fatigue effect via modulation of monoamines and the HPA axis, while Ashwagandha reduces cortisol and has a calming, sleep-supportive effect. Combined, they cover both the activating and the relaxing arms of the stress response.