Integrative Therapeutics Similase Review: Does It Actually Work?

Quick Verdict

I spent three weeks testing Similase digestive enzymes with breakfasts, lunches and heavier dinners, and the results surprised me. This Integrative Therapeutics formula isn't flashy — no gimmicky packaging, no celebrity endorsements — but the science behind it is solid. The broad pH-range microbial enzyme blend actually works across your entire digestive tract, not just one section. At 90 servings per bottle it's reasonably priced for a professional-grade supplement, and the vegan, dairy-free credentials are exactly what a lot of buyers are looking for. My score: 4.2 out of 5. It's not perfect, and I'll get into why, but for anyone dealing with occasional bloating, gas or sluggish digestion after meals, Similase is worth considering.

What Is Integrative Therapeutics Similase?

Similase is a comprehensive digestive enzyme supplement from Integrative Therapeutics — a brand that's been making professional-grade supplements since the 1990s. Unlike many enzyme products that rely on a single enzyme or a narrow blend, Similase uses a multi-enzyme formula derived from microbial sources. The advantage there is stability: microbial enzymes stay active across a wider pH range than animal-derived or plant-based alternatives, which tend to denature in stomach acid.

Each bottle contains 180 capsules — 90 servings at the recommended two-capsule dose. The formula targets carbs, proteins, fats, dairy sugars and fiber simultaneously. That breadth is the main selling point. If you've ever taken an enzyme supplement that only addressed one problem (say, lactase for dairy), you'll appreciate that Similase takes a more complete approach. The ingredients are clean: no dairy, no artificial colors, no artificial flavors, no preservatives. That's increasingly rare in a market flooded with over-processed supplements.

Key Features

• Broad-spectrum microbial enzyme blend active across a wide digestive pH range
• Supports digestion of proteins, carbs, fats, dairy and fiber in one formula
• Certified vegan and completely dairy-free
• Clean label — no artificial additives, colors or preservatives
• 180 capsules per bottle, 90 servings at standard two-capsule dose
• Manufactured by a brand with 25+ years of professional supplement experience
• Capsule form for easy swallowing with meals

Hands-On Review

I unboxed Similase on a Monday morning — the bottle has that no-nonsense clinical look that tells you right away this isn't a trendy wellness brand. No glossy influencers, no wellness-speak. Just a clean label with the enzyme breakdown listed plainly. I appreciated that immediately.

First week was a test run with standard meals. Breakfast (oatmeal, sometimes yogurt), lunch (sandwich or salad) and dinner (whatever my family was eating that night). I took two capsules with each meal, per the label. By day three, something shifted. The post-lunch heaviness I usually get around 2 PM — that foggy, bloated feeling after a decent-sized meal — was noticeably muted. I wasn't imagining it. My wife noticed I wasn't groaning on the couch after dinner anymore.

The second week I got bolder. Pizza night (high fat, high dairy), a big pasta bowl, even a meal out at a Thai restaurant known for rich curries. That's when I really put Similase through its paces. The pizza test was the most revealing: normally I pay for that kind of meal by hour three. This time? Nothing. No discomfort, no bloating, no waiting around regretting my choices. I felt genuinely impressed.

What surprised me was the 15-20 minute wait time. If you're expecting relief the moment you swallow, you won't get it. The enzymes need food in your stomach to work on. That's not a flaw — it's how enzyme supplements function — but it's worth knowing before you buy. I started keeping my Similase bottle next to the stove rather than my bedside, so I'd remember to take it at the start of cooking rather than halfway through a meal.

By week three, I'd settled into a rhythm: two capsules with anything bigger than a snack. A piece of fruit? Probably not necessary. A full dinner with sides and dessert? Definitely taking them. My only hesitation — and it's minor — is that the capsule is slightly larger than some other enzyme supplements I've tried. Nothing dramatic, but worth noting if you struggle with swallowing pills.

Who Should Buy It?

• Vegans and dairy-free households — if animal-derived enzymes are a dealbreaker, this checks every box. Clean credentials, no compromise on enzyme coverage.
• People with occasional bloating or heavy-meal discomfort — if a big dinner regularly leaves you uncomfortable, Similase's broad formula is well-suited to help.
• Those transitioning off dairy — the built-in lactase coverage can ease the adjustment period when you're reducing but not eliminating dairy entirely.
• Anyone already invested in gut health — if you're already taking probiotics or prebiotics and still experiencing gaps in your digestion, Similase fills a different niche: enzyme support rather than microbiome support.

Skip this if: you only have very mild, infrequent digestive hiccups — a simpler, cheaper single-enzyme product may be all you need. And if you've been diagnosed with a condition like chronic pancreatitis or exocrine pancreatic insufficiency, you need prescription enzymes, not an over-the-counter supplement like this. Similase isn't designed to replace medical treatment.

Alternatives Worth Considering

• NOW Foods Super Enzymes — a more budget-friendly broad-spectrum option with added bile salts. Less expensive, but uses animal-derived ox bile and isn't vegan-certified.
• Doctor's Best Digestive Enzymes — features a wide enzyme profile at a competitive price point. Vegan-friendly option available, though the formula differs from Similase's microbial focus.
• Pure Encapsulations Digestive Enzymes — a premium, practitioner-trusted brand with a clean label. Pricier per serving but some users prefer its targeted approach for specific digestive needs.

FAQ

Final Verdict

After three weeks with Integrative Therapeutics Similase, I'm confident recommending it — with the caveat that it works best for the right person. If you're vegan, dairy-free or just want a broad-spectrum enzyme that covers multiple digestive bases without a lot of filler, this is a formula you can trust. The microbial enzyme sourcing is genuinely smarter than the plant-based alternatives, and the fact that it stays active across your whole digestive tract rather than just one section makes a real-world difference.

It's not a magic pill. You still need to eat well, chew properly and give your body time. But on the days when meals get heavier than planned, Similase digestive enzymes give you a reliable fallback that won't let you down. For most people dealing with occasional digestive discomfort, it's earned its place in the supplement cabinet.