synergy
64 interactions related to synergy
vitamin a + vitamin d
Vitamins A and D share the RXR receptor partner, but the best human evidence shows high-dose preformed vitamin A can blunt vitamin D's effect on calcium and bone — the relationship is competitive, not a proven beneficial synergy. At ordinary dietary or multivitamin levels there is no meaningful problem.
boron + magnesium
Boron appears to help the body retain magnesium by reducing how much is lost in the urine, and both minerals support the activation of vitamin D and healthy bone metabolism. The combined human evidence is modest and partly context-dependent, but the pairing is low-risk and biologically plausible, with the strongest rationale for postmenopausal bone health.
vitamin d3 + vitamin k2
Vitamin D3 increases calcium absorption and stimulates production of vitamin K-dependent proteins (osteocalcin, matrix Gla protein) that require vitamin K2 to be activated. Taking the two together is a common, well-tolerated pairing that supports bone health. A separate, established interaction matters here: vitamin K2 reduces the effect of warfarin and other vitamin K antagonists.
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 markers of mitochondrial decay and improved memory more than either alone; strong direct evidence in humans is still limited.
coq10 + pqq
CoQ10 carries electrons in the mitochondrial electron transport chain to help produce ATP, while PQQ signals the cell to build new mitochondria via PGC-1alpha. Used together they support both the efficiency and the number of energy-producing mitochondria. The combination is well tolerated, with modest human evidence for cognitive and fatigue benefits.
curcumin + boswellia
Curcumin and boswellia act on complementary anti-inflammatory pathways (NF-kB/prostaglandins and 5-LOX/leukotrienes), and a randomized placebo-controlled trial found the combination eased knee osteoarthritis symptoms more than curcumin alone.
lemon balm + valerian
Lemon balm (Melissa officinalis) and valerian (Valeriana officinalis) both act on the brain's GABA system but at different points — valerian's valerenic acid nudges the GABA-A receptor while lemon balm's rosmarinic acid slows the enzyme that breaks GABA down — and the combination has been used as a gentle aid for restlessness and sleep difficulty. The effect is mild rather than pharmaceutical.
curcumin + ginger
Curcumin and ginger share overlapping anti-inflammatory mechanisms (COX-2 and NF-kB inhibition), with ginger adding 5-LOX blockade that curcumin lacks. The combination is favourable and complementary, with both contributing mild antiplatelet potential worth checking before combining with blood thinners.
niacin + coq10
Niacin (vitamin B3) is the precursor to NAD+ and NADH, the electron carriers that feed Complex I of the mitochondrial electron transport chain, where CoQ10 shuttles those electrons onward toward ATP synthesis. They support adjacent steps of the same energy-producing pathway, making them a plausible mitochondrial-support pairing. The combination has not been tested head-to-head in humans, so the benefit is biologically reasonable rather than proven.
zinc + copper
Zinc and copper are both essential trace minerals that share the same absorption machinery in the small intestine. Taken alone over time, sustained higher-dose zinc slowly works against your copper stores.
calcium + magnesium
Calcium and magnesium work together in bone mineralization, muscle contraction, and nerve signaling. They share some intestinal absorption pathways, so very large single doses of one can modestly reduce uptake of the other. A balanced intake of both, weighted toward food, supports bone health better than emphasizing calcium alone.
boron + calcium
Boron is an ultratrace mineral that appears to reduce urinary calcium loss and to support the activity of vitamin D, which governs how much calcium the gut absorbs. In short-term feeding studies of postmenopausal women, adding boron lowered urinary calcium excretion and modestly raised estradiol. The effect is supportive rather than dramatic and is most relevant when boron intake from food is low.
potassium + magnesium
Magnesium is required for the Na/K-ATPase pump that maintains intracellular potassium, so magnesium deficiency can cause potassium loss that does not correct with potassium alone until magnesium is also replaced. Both minerals independently support healthy blood pressure and cardiac rhythm, though the size of any added benefit from taking them together has not been well studied.
vitamin a + zinc
Zinc is required for the liver to synthesize retinol-binding protein, the carrier that moves vitamin A from liver stores into the bloodstream. When zinc is low, circulating vitamin A can stay low even though liver stores are adequate, and in deficient populations supplementing the two together corrects vitamin A status more reliably than vitamin A alone.
vitamin e + vitamin c
Vitamin C regenerates the active form of vitamin E. After vitamin E neutralizes a lipid free radical and becomes a tocopheroxyl radical, vitamin C donates an electron at the membrane surface to restore it. This recycling loop extends antioxidant capacity at the lipid-water interface of cell membranes. It is a beneficial synergy, not a risk.
vitamin b6 + vitamin b12
Vitamin B6 and vitamin B12 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. Taken together, they support both arms of homocysteine handling. Combination B-vitamin regimens lower homocysteine more reliably than single nutrients, though trials have not consistently shown reduced cardiovascular events.
vitamin b6 + folate
Vitamin B6 and folate both work inside one-carbon metabolism, the network that recycles homocysteine and supplies methyl groups. Folate (as 5-MTHF) remethylates homocysteine back to methionine, while B6 (as PLP) is the cofactor for serine hydroxymethyltransferase, which feeds the folate cycle, and for cystathionine beta-synthase, which clears excess homocysteine through the transsulfuration pathway. Folate carries the main homocysteine-lowering effect; B6's contribution shows up mainly after a protein (methionine) load rather than in fasting levels.
ashwagandha + magnesium
Ashwagandha helps dampen the body's stress-hormone response while magnesium supports the relaxation and nervous-system pathways that let the body wind down. The two act on different parts of the stress-and-sleep system, but no human trial has tested the specific combination, so any added benefit is inferred from each ingredient on its own rather than demonstrated together.
choline + vitamin b12
Choline (via its metabolite betaine) and vitamin B12 feed the two parallel pathways that recycle homocysteine back into methionine: the choline-betaine-BHMT route and the folate-B12-methionine-synthase route. Adequate choline can help maintain methylation through the BHMT pathway when B12 or folate status is marginal, supporting healthy homocysteine and SAMe levels. This is a benign nutritional synergy, not a risky combination.
l-theanine + caffeine
L-theanine, an amino acid from tea, appears to smooth out caffeine's stimulant effects by promoting alpha-wave brain activity associated with relaxed alertness, while caffeine blocks adenosine receptors to increase arousal. Human trials and a meta-analysis suggest the combination can improve sustained attention and reaction time more than either alone, with fewer of caffeine's jittery side effects.
vitamin b1 + magnesium
Magnesium is the cofactor that converts thiamine (vitamin B1) into its active coenzyme form, thiamine pyrophosphate (TPP). When magnesium is low, thiamine cannot activate fully, so a thiamine supplement may produce little benefit until magnesium status is restored. The two work together rather than against each other.
phosphatidylserine + omega-3
Phosphatidylserine and omega-3 fatty acids (especially DHA) are both core structural components of neuronal membranes, and a PS-DHA form mirrors the way the two naturally occur together in brain phospholipids. In older adults with subjective memory complaints, supplementing the pair has shown modest, mostly subgroup-level improvements in memory measures, though the strongest single figures come from small, uncontrolled studies and the placebo-controlled evidence is weaker than the synergy is sometimes presented to be.
ashwagandha + l-theanine
L-theanine, an amino acid from green tea, produces a relatively quick sense of calm focus by increasing alpha brain-wave activity and gently nudging GABA and other neurotransmitters. Ashwagandha works more slowly, modulating the stress (HPA) axis over weeks of daily use. Because they act through different pathways on different timescales, they are commonly stacked for stress, and there is no known harmful interaction. Importantly, no human trial has tested the combination itself, so the pairing is a mechanistic rationale rather than a proven synergy.
gaba + l-theanine
GABA and L-theanine are often combined in sleep supplements, and the pair may help you fall asleep a little faster and rest more soundly than either alone. The evidence is modest: an animal study and one small uncontrolled human study suggest a benefit, but no controlled human trial has confirmed a true synergy. Both compounds can add to the effects of alcohol and sedatives, so review the combination with your doctor or pharmacist if you take sleep, anxiety, or blood-pressure medication.
omega-3 + curcumin
Omega-3 fatty acids (EPA and DHA) and curcumin lower inflammation through complementary pathways — omega-3s remodel cell membranes and generate specialized pro-resolving mediators, while curcumin inhibits NF-kB and downstream inflammatory cytokine signaling. Human trials in migraine patients show the combination can reduce inflammatory markers more than either alone.
melatonin + magnesium
Melatonin provides a circadian timing signal while magnesium supports a calmer nervous system, so the two target different parts of the sleep problem and are commonly combined. The pairing is generally well tolerated short term, though rigorous proof of a specific two-ingredient synergy is limited.
passionflower + lemon balm
Passionflower (Passiflora incarnata) and lemon balm (Melissa officinalis) are both traditional calming herbs that act on the brain's GABA system - the main "slow down" signalling network. In laboratory studies, passionflower flavonoids appear to make GABA-A receptors more responsive, while lemon balm compounds appear to slow the breakdown of GABA. Because both lean in the same calming direction, taking them together is plausibly additive. There is, however, no human trial of this specific two-herb pair, so any combined benefit is theoretical and likely mild. The practical point is the shared sedative tendency: combining them with each other, or with other sedatives, can add up.
glutathione + vitamin c
Glutathione and vitamin C participate in the same cellular antioxidant network and help regenerate one another. When vitamin C is oxidised to dehydroascorbate, glutathione donates electrons to convert it back to active ascorbate; in turn, vitamin C helps keep glutathione in its active reduced form. The two are commonly supplemented together and the combination is well tolerated, though clinical benefit beyond the established biochemistry is modest and not consistently proven.
nac + vitamin c
NAC and vitamin C touch the same antioxidant network on paper, but the human evidence for taking them together is mixed: a controlled trial found the combination raised oxidative stress and tissue-damage markers after acute muscle injury rather than protecting against them.
nac + selenium
NAC supplies cysteine, the rate-limiting building block for glutathione synthesis, while selenium is the cofactor built into the glutathione peroxidase enzymes that use glutathione to neutralize peroxides. The two nutrients support the same antioxidant pathway, so on a mechanistic level each helps the other work. Combined clinical benefit beyond that shared pathway is not well demonstrated, and the pairing is low-risk.
hyaluronic acid + collagen
Hyaluronic acid and collagen are the two dominant structural components of the skin's extracellular matrix — collagen provides tensile strength while hyaluronic acid binds water and provides cushioning. Each, taken orally, has human trial support for modest improvements in skin hydration and elasticity, and they act on the same tissue from complementary angles. A true additive benefit over either ingredient alone has not been proven in humans, so the pairing is best treated as plausible and low-risk rather than a confirmed synergy.
msm + glucosamine
MSM and glucosamine feed the same biochemical pipeline that builds and maintains healthy joint tissue, so they complement rather than compete. This is a beneficial pairing, not a harmful interaction.
collagen + vitamin c
Vitamin C is a required 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 (or gelatin) together with a source of vitamin C supplies both the amino acid building blocks and the enzymatic cofactor the body needs to assemble functional new collagen. This is a benign nutritional synergy, not a risk.
hawthorn + coq10
Hawthorn (Crataegus) flavonoids and oligomeric procyanidins act on the mechanical and vascular side of heart function, while CoQ10 supports the heart's energy metabolism in the electron transport chain. The two are sometimes combined as low-risk cardiovascular adjuncts, but the supportive human evidence is for each ingredient separately, not for the pair, so any "synergy" is extrapolated rather than demonstrated.
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 acts as a lipid-soluble antioxidant that helps protect omega-3 fatty acids from peroxidation both during storage and after absorption, which is why most quality fish oils already include a small amount of mixed tocopherols.
l-arginine + l-citrulline
L-arginine is the direct precursor to nitric oxide, but a large share of an oral dose is degraded by intestinal arginase and first-pass liver metabolism, so plasma levels peak quickly and fall within an hour or two. L-citrulline largely bypasses that metabolism and is converted to L-arginine in the kidneys, sustaining the rise for longer. Taken together they raise plasma arginine higher and for longer than either alone, supporting nitric-oxide-dependent effects.
curcumin + fat
Curcumin is a lipophilic molecule with very low water solubility, and dietary fat improves its dissolution and incorporation into bile-acid micelles for intestinal absorption. Taking curcumin or turmeric with a fat-containing meal, and using lipid-based formulations, raises its plasma exposure compared with intake on an empty stomach.
iron + vitamin a
Vitamin A and beta-carotene appear to improve absorption of non-heme iron from plant foods by forming soluble complexes with iron that keep it from binding to phytates and polyphenols in the gut. In controlled human absorption studies, adding vitamin A to a grain-based meal increased the amount of iron absorbed.
fat-soluble vitamins + dietary fat
Vitamins A, D, E, and K depend on bile-driven micelle formation in the small intestine to be absorbed, and that process is triggered by dietary fat. Taking these vitamins with a fat-free meal or on an empty stomach reduces how much you absorb, while taking them with a meal that contains some fat improves absorption. Controlled studies in vitamin D show meaningfully greater absorption when the supplement is taken with fat.
spermidine + resveratrol
Spermidine and resveratrol both promote autophagy but reach it through different upstream routes: spermidine inhibits acetyltransferases while resveratrol activates the deacetylase SIRT1, converging on the cell's acetylproteome. In human cells, yeast, and nematodes, low concentrations that did nothing alone induced autophagy when combined, so the two are biologically plausible partners. Human clinical evidence for the combination is lacking, so any longevity stack should be treated as a low-stakes complement to diet, sleep, and exercise rather than a proven intervention.
turmeric + black pepper
Piperine, the active alkaloid in black pepper, slows the gut and liver enzymes that normally inactivate curcumin (the main bioactive in turmeric). Taking the two together substantially increases how much curcumin reaches the bloodstream, which is why piperine is one of the most common absorption enhancers in turmeric supplements. The same enzyme effect can also raise levels of some prescription drugs, so concentrated daily supplement doses warrant a pharmacist check for people on chronic medications.
caffeine + tyrosine
L-tyrosine is a precursor to the catecholamine neurotransmitters (dopamine, norepinephrine), and caffeine indirectly amplifies catecholamine signaling by blocking adenosine receptors. The pairing is popular as a focus stack, but the direct evidence is limited: tyrosine alone helps preserve cognition under stress or sleep loss, and caffeine aids alertness, yet no human trial has tested caffeine plus tyrosine on their own. The combination is generally well tolerated in healthy adults, with the main cautions involving MAO inhibitors, levodopa, and thyroid medication.
nad+ + niacin
Niacin (nicotinic acid) is a vitamin B3 form the body converts to NAD+ through the Preiss-Handler pathway, so pairing low, vitamin-level niacin with a direct NAD+ precursor gives cells more than one biosynthetic route to build their NAD+ pool. Niacin has been shown to raise muscle and blood NAD+ in mitochondrial myopathy, though no human trial has tested combining it with direct NAD+, NR, or NMN — the synergy is plausible additive biology rather than a proven stack.
lycopene + fat
Lycopene is a fat-soluble carotenoid whose absorption depends on incorporation into bile-acid micelles, which require dietary fat. Human studies show that eating lycopene-rich foods with a fat source — such as olive oil or avocado — substantially increases how much lycopene reaches the bloodstream.
boswellia + omega-3
Boswellic acids inhibit 5-lipoxygenase to reduce pro-inflammatory leukotrienes, while EPA and DHA from omega-3s lower the arachidonic acid available to inflammatory enzymes and serve as substrates for specialized pro-resolving mediators (resolvins, protectins) that help switch inflammation off. The two act at different steps of the same lipid cascade, giving complementary anti-inflammatory coverage. Evidence in joint pain is modest but consistent.
vitamin k2 + calcium
Vitamin K2 activates osteocalcin and matrix Gla protein, two proteins that bind calcium and help direct it into the bone matrix while keeping it out of arterial walls. Taking calcium alongside adequate vitamin K2 supports bone health; the two nutrients work together rather than competing.
l-theanine + magnesium
L-theanine and magnesium are both gentle, non-sedating relaxants that act on the same nervous-system pathways from different angles: L-theanine raises alpha-wave activity and modestly increases GABA, serotonin and dopamine, while magnesium dampens NMDA-receptor excitation and supports GABA-A signalling. A single preclinical study (Dasdelen et al., Frontiers in Nutrition, 2022) found a magnesium-L-theanine complex outperformed L-theanine alone in rats, but no human trial has tested the combination, so the pairing is reasonable rather than proven synergistic in people.
vitamin b12 + folate
Vitamin B12 and folate are interdependent partners in the methionine cycle: the active form of folate (5-methyltetrahydrofolate) donates a methyl group, while vitamin B12 is the required cofactor for methionine synthase, the enzyme that converts homocysteine back to methionine. Adequate intake of both supports DNA synthesis, healthy red blood cells, and homocysteine balance. Taking high-dose folate alone is the key safety concern, because folate can correct B12-deficiency anemia while allowing nerve damage to progress unnoticed.
niacin + tryptophan
Niacin (vitamin B3) and the amino acid tryptophan are nutritionally linked: the body can make niacin from tryptophan through the kynurenine pathway, so the two together support the NAD/NADP coenzyme pools that power energy metabolism. Adequate niacin also frees up tryptophan for serotonin and melatonin production. This is a beneficial nutritional partnership, not a hazardous interaction.
ginkgo + phosphatidylserine
Pairing a standardized ginkgo biloba extract with phosphatidylserine appears to improve absorption of ginkgo's active fraction. In one small placebo-controlled crossover trial, the ginkgo-phosphatidylserine complex produced modest improvements in memory performance and speed in healthy young adults, where the same dose of ginkgo alone did not.
ashwagandha + reishi
Ashwagandha and reishi are complementary adaptogens often combined in stress-and-sleep formulas. Ashwagandha calms the HPA axis and cortisol output, while reishi supports parasympathetic and immune balance. They act through different routes, so the effects layer rather than collide. This is a low-risk, complementary pairing rather than a dangerous drug interaction.
nac + glutathione
NAC (N-acetylcysteine) supplies cysteine, the rate-limiting building block the body uses to make its own glutathione, while supplemental glutathione adds to the existing pool. Both support antioxidant defense, and the pairing is generally well tolerated. Human trial evidence for raising glutathione comes mainly from NAC (often with glycine, as GlyNAC), not from combining NAC with oral or liposomal glutathione, and no study has shown the pair works better than either one alone.
magnesium + glycine
Magnesium and glycine are commonly combined as magnesium bisglycinate, a chelate whose clearest benefit is being gentle on the gut and improving adherence, rather than dramatically higher absorption.
selenium + iodine
Iodine is the raw material the thyroid uses to build the hormones T4 and T3, but selenium is required to make the deiodinase enzymes that convert inactive T4 into active T3 in peripheral tissues. Selenium also powers glutathione peroxidase, which protects thyroid cells from the oxidative stress generated during iodine handling. The two minerals work as a pair: each is far less useful without the other.
vitamin b6 + magnesium
Vitamin B6 and magnesium are nutritional partners: magnesium is needed to activate B6 into its coenzyme form, and B6 appears to support magnesium's uptake into cells. Randomized trials suggest the pair can ease premenstrual and stress-related symptoms somewhat better than magnesium alone, especially in people running low on magnesium. The effect is modest and beneficial, not a safety concern.
curcumin + quercetin
In laboratory intestinal-cell models, quercetin slows the gut and liver enzymes (UDP-glucuronosyltransferase and CYP3A4) that normally break curcumin down quickly, which raised curcumin's measured permeability across the cell layer. Both polyphenols also act on overlapping anti-inflammatory and antioxidant pathways. The evidence is mechanistic and limited to in vitro work — no human trials have confirmed a real-world bioavailability or anti-inflammatory benefit from combining them.
choline + inositol
Choline and inositol are classic lipotropic nutrients that each support how the liver handles fat. Choline is needed to package triglycerides into VLDL particles for export from the liver, while inositol contributes to phosphatidylinositol membranes and insulin signaling. Each has independent evidence for supporting liver lipid metabolism, but the specific benefit of combining them has not been demonstrated in humans, so the pairing is best viewed as low-risk and complementary rather than proven synergy.
garlic + hawthorn
Garlic and hawthorn each modestly lower blood pressure on their own, and both have mild blood-thinning activity, so taking them together can add up to a slightly larger drop in blood pressure and a small increase in bleeding tendency. There is no human trial of the two taken together, so any true 'synergy' beyond simple additive effects is unproven. The practical concern is layering them on top of antihypertensive, antiplatelet, or anticoagulant medication.
acetyl-l-carnitine + coq10
Acetyl-L-carnitine (ALCAR) helps shuttle long-chain fatty acids into mitochondria for beta-oxidation, and CoQ10 carries the resulting electrons through the respiratory chain. The two act at complementary steps of mitochondrial energy production. The human trials people cite for this pairing actually test multi-nutrient cocktails (with alpha-lipoic acid and B vitamins), not ALCAR plus CoQ10 alone, so any combined benefit in healthy people is likely subtle. Both ingredients have a long safety record and no clinically important interaction with each other.
fisetin + quercetin
Fisetin and quercetin are structurally related dietary flavonols with overlapping antioxidant and anti-inflammatory activity, both studied as candidate senolytics. They are often combined in longevity-oriented supplement stacks, but the robust human senolytic evidence is for dasatinib plus quercetin, not for the fisetin-plus-quercetin pairing, which rests largely on animal and mechanistic data. The combination is generally well tolerated; the main practical consideration is that both flavonoids can affect platelet function and drug metabolism, so anyone on prescription medication should check with a clinician.
pomegranate + ace inhibitors
Pomegranate juice modestly lowers blood pressure on its own and can add to the blood-pressure-lowering effect of ACE inhibitors; it also contributes dietary potassium, which may compound the potassium-retaining effect of these drugs.
vitamin e + selenium
Vitamin E and selenium are complementary antioxidants. Selenium is the cofactor for glutathione peroxidase, which clears lipid peroxides and spares vitamin E, while vitamin E intercepts free radicals in membranes and reduces the demand on the selenium-dependent enzyme. The partnership is well established in animal and mechanistic studies; clinical benefit of the combination in people is more limited.
saffron + curcumin
Saffron (Crocus sativus) and curcumin (from turmeric) both have antidepressant effects through partly complementary mechanisms: saffron modulates serotonin and dopamine reuptake and increases BDNF, while curcumin reduces neuroinflammation, supports monoamine balance, and normalizes the HPA axis. A randomized, double-blind, placebo-controlled trial found a saffron plus curcumin combination significantly improved depressive symptoms versus placebo in adults with major depression.
rhodiola + ashwagandha
Rhodiola rosea and ashwagandha are both adaptogens that act through different mechanisms. Rhodiola tends to be energizing and anti-fatigue, working on monoamines and the HPA axis, while ashwagandha tends to be calming and helps normalize cortisol. Many people pair them so that rhodiola covers the activating, daytime side of the stress response and ashwagandha covers the calming, evening side. No trial has tested the exact combination, so the rationale is mechanistic rather than proven.