Best Supplements by Goal (Insulin Resistance, Post-GLP-1, Perimenopause, Aging Lifter)

A direct framing before we get into product picks: most adults don't need supplements. A whole-foods diet with adequate protein, sleep, and sun exposure handles the substantive nutrient needs of healthy adults. The supplement industry is substantially larger than the actual use case justifies.

That said, specific goals and conditions do benefit from targeted supplementation. This guide covers the evidence-backed picks for four common scenarios. We're not selling daily multivitamins or generic "wellness stacks" — those have weak evidence and unclear value for most users.

The framework

We rank supplements in three tiers:

• Tier 1 — strong evidence: well-studied, consistent benefit for the target population, low risk of harm
• Tier 2 — moderate evidence: plausible benefit, some studies support, worth considering
• Tier 3 — emerging: mechanism makes sense, limited human data, judge case-by-case

We don't recommend Tier 3 supplements as default. They're listed where relevant for specific cases.

Insulin resistance

The mechanism: reduce ectopic lipid in liver and muscle (Petersen-Shulman framework), improve glucose disposal, reduce postprandial spikes. Diet and resistance training are the levers; supplements are supplementary.

Tier 1:

Magnesium glycinate or magnesium citrate, 200–400 mg daily. Magnesium is depleted in many adults with insulin resistance, and supplementation improves insulin sensitivity in deficient patients. Glycinate is gentler on GI; citrate has a mild laxative effect (can help if constipated). Avoid magnesium oxide (poor absorption).

Brands: Thorne, Pure Encapsulations, Designs for Health.

Vitamin D3 + K2. Vitamin D deficiency is associated with insulin resistance; D3 supplementation in deficient adults improves insulin sensitivity. K2 (MK-7 form) supports calcium handling and bone density. Target: D3 2,000–4,000 IU daily with food, K2 100–200 mcg daily. Get a 25(OH)D blood test annually to confirm levels above 30 ng/mL.

Tier 2:

Berberine, 500 mg 2–3x daily. Plant alkaloid with insulin-sensitizing effects similar in magnitude to metformin in some trials. The mechanism involves AMPK activation. Useful for prediabetics or adults with HbA1c in the 5.7–6.4% range. Quality matters substantially — many brands have low-grade extract.

Inositol (myo + d-chiro), 4 g daily. Particularly useful for PCOS patients, where the evidence is strongest. Improves ovulation and reduces androgen excess.

Tier 3 (case-by-case):

• Alpha-lipoic acid (300–600 mg daily) — older evidence; still occasionally useful
• Chromium picolinate — minimal additional benefit beyond food sources for most
• Curcumin — anti-inflammatory; some insulin-sensitivity data; quality varies wildly

What we don't recommend:

• Apple cider vinegar pills — modest mechanism, limited clinical effect, takes capacity away from real interventions
• "Insulin support" blends with proprietary formulas — the proprietary blend usually contains too little of each active ingredient to matter

Post-GLP-1 recovery

The mechanism: counter the lean-mass and bone-density loss documented in Linge 2024 and Jensen 2024. The lever is protein adequacy plus resistance training; supplements support specific deficits.

Tier 1:

Whey protein isolate, 25–30 g per serving. When food intake is suppressed (especially during peak appetite suppression), hitting the 1.8–2.0 g/kg target requires supplementation. Whey isolate is faster-absorbing, lower in lactose (reduced GI burden), and the highest leucine concentration per gram.

Brands: Equip Foods (Saladino's grass-fed brand), Naked Whey, Trans4orm Naturals, or any unflavored whey isolate without seed-oil-based "creamers" or proprietary blends.

Creatine monohydrate, 5 g daily. One of the most-studied supplements ever. Preserves muscle mass and strength during caloric deficit, supports cognitive function in older adults, low risk of harm. Take any time of day with food; loading phase isn't necessary. Brand doesn't matter — buy the cheapest "Creapure" certified version.

Vitamin D + K2 (as above). The bone-density loss documented in Jensen 2024 is the specific reason this matters for GLP-1 users. Combined with resistance training, this is the protocol.

Calcium 1,000–1,200 mg/day (food first; supplement only if food intake is consistently below target). Particularly important for women on GLP-1s.

Tier 2:

Collagen peptides, 15–20 g daily. Supports skin and connective tissue during rapid weight loss (the "ozempic face" issue). Mechanism is via providing glycine and proline. Modest benefit; reasonable to add if budget allows.

B12, 500–1,000 mcg sublingual daily. Some GLP-1 users develop B12 absorption issues from gastric-emptying delay. Test annually; supplement if levels drop below 400 pg/mL.

Perimenopause

The mechanism: support bone density, mood, sleep, and metabolic stability through hormonal turbulence. The lever is HRT (when appropriate, with a knowledgeable physician), resistance training, and protein adequacy. Supplements are supportive, not curative.

Tier 1:

Vitamin D3 + K2 (as above). Bone density loss accelerates 1–2% per year through perimenopause. D3 + K2 + resistance training + adequate calcium is the protocol.

Magnesium glycinate, 300–400 mg before bed. Substantial evidence for sleep quality improvement. Many perimenopausal women have suboptimal magnesium status. Glycinate form is calming; works well for sleep.

Calcium, 1,200 mg/day (food first; supplement only if food intake is below target).

Omega-3 (EPA + DHA), 1–2 g daily. Supports mood, joint comfort, and cardiovascular health. Wild fish 2–3x weekly handles this; supplementation when fish intake is low. Pick brands with low-oxidation testing.

Tier 2:

Creatine monohydrate, 5 g daily. Underdiscussed for women but well-supported. Improves training output, may benefit cognitive function during hormonal turbulence.

Black cohosh (40–80 mg daily) — for hot flashes and night sweats. Some women respond well, others don't. Worth a 12-week trial if HRT isn't an option.

Maca root (1.5–3 g daily) — for libido and energy. Modest evidence; reasonable to try.

Tier 3:

• Ashwagandha — for stress and sleep. Some women respond; thyroid patients should be cautious.
• Pregnenolone — precursor hormone supplementation. This is essentially DIY HRT-light; please consult a physician before using.

What we don't recommend without a physician:

Any phytoestrogen (red clover, dong quai, etc.) at therapeutic doses. The interaction with native estrogen levels and HRT (if used) is more complex than the supplement marketing suggests.

Aging lifter (45+)

The mechanism: counter anabolic resistance, support recovery, maintain training output. The lever is resistance training plus adequate protein.

Tier 1:

Creatine monohydrate, 5 g daily. Strongest evidence in this population. Preserves muscle mass, supports cognitive function in older adults, may reduce sarcopenia trajectory.

Whey protein when food protein is inadequate. Older adults need ~30–40 g protein per meal to trigger MPS reliably (anabolic resistance). When meal protein is consistently below threshold, a whey shake bridges the gap.

Vitamin D3 + K2 (as above). Bone density support; consistent benefit in older adults with deficient baseline.

Omega-3, 1–2 g EPA+DHA daily. Joint comfort, cardiovascular support, recovery. Substantial evidence base in older athletes.

Tier 2:

Magnesium glycinate, 200–400 mg before bed. Sleep, recovery, and many older adults have suboptimal status.

Collagen peptides, 15–20 g daily. Joint comfort, especially with high-volume training. Modest evidence; many users report subjective benefit.

HMB (β-hydroxy β-methylbutyrate), 3 g daily. Particularly useful for older adults during caloric deficit or extended training breaks. Reduces muscle protein breakdown.

Tier 3:

• Beta-alanine (3–5 g daily) — for high-rep training; modest evidence
• Ashwagandha — recovery and cortisol regulation; reasonable trial
• Tongkat ali — testosterone support in older men; emerging evidence

What we don't recommend:

• Pre-workout stimulant blends (most are over-caffeinated UPF)
• "Test booster" supplements — almost universally weak evidence
• Daily multivitamins — most adults get sufficient vitamins from a varied diet; megadoses of certain vitamins (especially A, E) may be harmful long-term

Brand quality matters

A few notes on brand quality, because the supplement industry has wildly variable QC:

Worth premium pricing:

• Practitioner brands like Designs for Health, Thorne, Pure Encapsulations — these brands have third-party testing, FDA-registered facilities, and are generally trusted by clinicians.

• Heart & Soil — for organ-meat-based supplements (liver, kidney, heart capsules). Saladino-affiliated; transparent sourcing.

• Equip Foods — for protein and supplemental nutrition. Saladino-affiliated; clean ingredient lists.

Acceptable mass-market:

Most major brands (Now Foods, Jarrow, Nordic Naturals for fish oil, Klean Athlete) have reasonable QC. Read labels for unnecessary additives.

Avoid:

• Amazon "supplement" brands without verifiable QC
• Multi-level marketing (MLM) supplements — the price markup goes to the network, not the product quality
• Anything with proprietary blends that don't disclose individual ingredient amounts
• Products with massive ingredient lists (a "comprehensive" multi-something with 30+ ingredients usually means tiny doses of each)

What to test before supplementing

Several common deficiencies are worth testing rather than blanket-supplementing:

• 25(OH)D — for vitamin D status (target above 30 ng/mL, ideal 40–60)
• Ferritin — for iron status (often low in menstruating women, athletes)
• B12 — particularly for older adults, vegans, and GLP-1 users
• Magnesium (RBC magnesium, not serum) — serum magnesium is a poor measure
• TSH, Free T3, Free T4 — for thyroid status (especially women)
• Lipid panel + ApoB — for cardiovascular risk

Testing once per year is usually sufficient unless you're addressing a specific issue. Most major insurance covers these; the cash-pay versions through services like LetsGetChecked or Quest run $50–150 for a basic panel.

What we deliberately don't promote

A few categories where the evidence doesn't justify the marketing:

• Detox / cleanse products — your liver detoxifies continuously; supplements don't enhance the function in healthy adults
• Adrenal support / cortisol balance — stress management matters; supplements don't fix HPA-axis dysregulation
• Greens powders — most are expensive for what they deliver; eat actual vegetables
• Premade nootropics stacks — individual ingredients matter; pre-formulated blends rarely contain effective doses
• CBD as a general "wellness" supplement — specific use cases (sleep, pain) have moderate evidence; the universal "good for everything" framing isn't supported

The honest summary

For most adults, the supplement framework is:

1. Vitamin D + K2 — most adults benefit, especially in northern latitudes
2. Magnesium glycinate — common deficit, low cost, low risk
3. Omega-3 — when fish intake is below 2x weekly
4. Creatine — for anyone training resistance, especially older adults
5. Whey protein — when food protein is insufficient

That's the universal stack: $30–50/month total, well-supported, low risk. Beyond that, specific goals warrant specific additions as outlined above.

If you're spending more than $100/month on supplements, examine what's actually moving the needle vs what's expensive marketing. Most of the supplement industry is the latter.