Supplement Interaction Matrix

Visual guide showing which supplements work together (synergies) and which to avoid combining (conflicts). Interactive matrix with 100+ supplements.

-- Supplements
-- Synergies
-- Conflicts
-- Caution Pairs
Filter:
Synergy - enhances effect
Conflict - avoid combining
Caution - compete for absorption
Neutral - no known interaction

Loading supplement data...

Scroll horizontally and vertically to explore. Click a cell for details.

Disclaimer: This tool is for educational purposes only. Always consult a qualified healthcare provider before starting, stopping, or combining any supplements, especially if you take prescription medications.

What the Interaction Matrix does

The Interaction Matrix is a visual grid of 100+ supplements showing, at a glance, how every pair behaves together. Each cell tells you one of four things:

  • 🟢 Synergy — the pair works better together (e.g., Vitamin D + K2, Iron + Vitamin C).
  • 🟡 Caution — fine together, but space them out by a few hours.
  • 🔴 Conflict — don’t combine; one cancels or weakens the other.
  • ⚪ Neutral — no meaningful interaction in either direction.

Where the Stack Analyzer answers “what’s wrong with my stack?”, the matrix answers “is X safe with Y?” — fast lookup, no inputs to fill in.

How to use it

  1. Find one supplement along the top row or left column.
  2. Find the other on the perpendicular axis.
  3. Read the cell where they intersect — color and icon tell you the relationship at a glance.
  4. Click the cell for the detailed explanation: mechanism, spacing recommendation, and the strength of the underlying evidence.
  5. Filter the matrix by category (vitamins, minerals, herbs, amino acids, peptides) to shrink the grid when you only care about a subset.

Tip: hover (or tap on mobile) the row/column header to highlight the whole row/column — useful when you want every interaction involving a single supplement.

Examples

Looking up: “Can I take Zinc with Copper?”

Find Zinc → Copper. The cell is 🟡 Caution. Reason: long-term high-dose Zinc (>40 mg/day) depletes Copper because they share the same transporter. Most multi-mineral formulas correct for this with a Zinc:Copper ratio around 15:1.

Looking up: “Is Calcium safe with Iron?”

🔴 Conflict. Calcium reduces non-heme iron absorption by 40–60% when taken in the same window. Take them at least 2 hours apart — Iron with breakfast (preferably with Vitamin C), Calcium with dinner.

Looking up: “Vitamin D and Magnesium?”

🟢 Synergy. Magnesium is a cofactor for converting Vitamin D into its active form. Taking high-dose D without enough Magnesium can actually deplete Magnesium stores.

The 12 highest-impact interactions to memorize

If you don’t have time for the whole matrix, these are the 12 pairs that explain ~80% of the absorption and safety issues we see. They’re worth committing to memory.

🟢 Synergies (take together or close)

  1. Vitamin D3 + Vitamin K2 — D3 raises Calcium; K2 routes it to bone instead of arteries. Standard pair: 5,000 IU D3 + 90–180 mcg K2 (MK-7).
  2. Iron + Vitamin C — Vitamin C 3–5× the iron dose roughly triples non-heme iron absorption. Take together at breakfast.
  3. Vitamin D3 + Magnesium — Magnesium is the cofactor that activates D3. High-dose D without enough Magnesium silently depletes Magnesium stores.
  4. Curcumin + Black Pepper (Piperine) — Piperine increases Curcumin bioavailability ~20×. Most quality Curcumin products bundle ~5 mg Piperine.
  5. L-Theanine + Caffeine — L-Theanine smooths Caffeine’s edge without cutting alertness. 2:1 ratio (200 mg L-Theanine + 100 mg Caffeine) is the most-studied dose.

🟡 Caution — fine, but space them out

  1. Zinc + Copper — long-term Zinc >40 mg/day depletes Copper. Add ~1 mg Copper per 15 mg Zinc, or pick a combo formula.
  2. Magnesium + Calcium — competes for absorption above ~500 mg each. Split AM/PM if you take both at higher doses.
  3. Zinc + Magnesium — also share transporters. Take Zinc on empty stomach AM, Magnesium PM with food.

🔴 Conflicts — don’t combine in the same window

  1. Calcium + Iron — Calcium cuts non-heme iron absorption by 40–60%. Take 2+ hours apart.
  2. Calcium + Zinc — same transporter. A 30 mg Zinc with 1,000 mg Calcium delivers ~12–15 mg effective Zinc.
  3. Iron + Coffee/Tea — tannins block iron absorption by up to 60%. Take iron 1 hour before or 2 hours after caffeine.
  4. Calcium/Iron/Magnesium + Levothyroxine — minerals reduce thyroid med absorption sharply. Take Levo on empty stomach AM, minerals 4+ hours later.

Color-coding quick reference

MeaningWhat to do
🟢Synergy — better together than aloneTake in the same window; same meal is fine
🟡Caution — fine but not at the same momentSpace by 2–4 hours; the cell detail panel gives the exact gap
🔴Conflict — one cancels or weakens the otherMove to different parts of the day; rarely “never combine” — usually just “separate”
⚪Neutral — no meaningful interactionTake whenever fits your schedule

FAQ

How is this different from the Stack Analyzer?The matrix is for **single-pair lookups**: "is X okay with Y?" The Stack Analyzer takes your whole stack and runs the analysis across every pair, plus checks for gaps and builds a timing schedule. Use the matrix when you have one quick question; use the analyzer when you're planning your stack.
What does "spacing" mean — is the pair safe or not?🟡 Caution pairs are safe to take, just not at the same moment. If two supplements compete for the same absorption pathway, taking them 2–4 hours apart lets each get its share. The detail panel for each Caution cell gives the recommended gap.
Why are some cells "Neutral" — does that really mean nothing happens?Neutral means no clinically meaningful interaction has been documented in either direction. It doesn't mean "literally zero biochemistry," it means you can take them together without measurable absorption loss or safety concern.
Does the matrix cover prescription drugs?No — this matrix is supplement-to-supplement only. For supplement-to-medication interactions, use the Medication Checker instead.
How often is the matrix updated?We refresh interactions as new research lands — typically a small update every month and a broader review each quarter. The "last updated" date for each pair is shown in its detail panel.